What do International City Networks Contribute to Global Governance? Towards a Better Conceptual and Empirical Assessment

ABSTRACT

This article systematically assesses international city networks (ICNs) and their contribution to global governance. Research in urban studies has frequently emphasised the growing number and activities of ICNs in global politics, particularly environmental politics. However, systematic and comparative assessments of their main characteristics and how they contribute to global governance in different issue areas remain rare. To advance our conceptual, empirical, and comparative understanding of these networks, we review existing approaches and analyse a sample of 30 ICNs concerning three categories, namely their structures, aims, and activities. The results show that ICNs assemble diverse actors, closely collaborate with international organisations, and are dedicated to the implementation, but also the change of global norms in several issue areas of global governance. At the same time, the results suggest that more empirical data and comparative analyses of ICNs are necessary to advance our conceptual understanding of ICNs and their relevance in global governance.

KEYWORDS:

• Global governance
• networks
• global norms
• implementation
• urban politics

1. Introduction

What are international city networks, and how do they contribute to global governance? In this article, we assess and compare the structures, aims, and activities of international city networks (ICNs) to specify the relevance of ICNs for global politics. So far, existing research at the intersection of urban studies – a multidisciplinary research programme that typically analyses cities in all aspects – and International Relations (IR) emphasises the significance of municipal actors in international affairs: City governments, mayors, or experts from city administrations regularly engage in practices of so-called “city diplomacy” with different counterparts in various issue areas (see Acuto 2013; Curtis 2014; Smith 2019; Tavares 2016). Particularly, cities build institutionalised relations through networks to bring urban perspectives into processes of global governance (Acuto et al. 2021; Acuto and Rayner 2016; Bouteligier 2014). In addition to such bottom-up city initiatives, international organisations increasingly identify cities as partners for the local implementation of their global policies. As a result, both global organisations and specialised agencies (such as the UN or WHO), as well as regional organisations like the EU cultivate a broad variety of programmes, partnerships, and fora for cities, supporting their networking efforts (Kosovac, Acuto, and Jones 2020; Tavares 2016). Especially in global environmental politics, city networks and international organisations cooperate closely, which can result in common agenda-setting and implementation (Acuto and Rayner 2016; Davidson, Coenen, and Gleeson 2019; Fraundorfer 2017). For example, the climate initiative C40 translates global ideas to the local realm, and some researchers even argue that the members of this network are more determined than national governments to implement global norms on combatting climate change (Bouteligier 2013; Coenen, Davidson, and Gleeson 2019; Johnson, Toly, and Schroeder 2015). Yet, even if cities shape international affairs, they usually have neither “a seat at the top table” (Acuto 2016) nor a formal role in global politics (Acuto et al. 2021; Kosovac et al. 2021). It is, therefore, essential to understand how cities and their networks affect international politics without reinforcing highly optimistic accounts of their agency that consider them the spearhead in global affairs in opposition to “dysfunctional nations” (Barber 2013; critically: Acuto 2019; Bassens et al. 2019). This article aims to advance the theoretical and empirical understanding of city networks for global governance.

While seminal studies in the 1990s (Castells 1996; Sassen 1991) conceptualised cities as places with a specific economic capacity in the global economy, more recent accounts focused on the activities of mayors and cities as the unit of analysis in international affairs (Barber 2013; Curtis 2016; Gordon and Ljungkvist 2022; Ljungkvist 2016; Szpak et al. 2022). Those scholars who focus on the network level typically analyse these networks against a background of environmental politics (Bansard, Pattberg, and Widerberg 2017; Gordon 2020; Hickmann 2021). As underlined in urban studies, these networks represent a more substantial international engagement than the well-known bilateral city partnerships or twin city programmes. Although studies examine subnational networking activities in many details and with significant findings, “transnational municipal networks” – a long-standing term in urban studies (Durmus and Oomen 2022; Kern and Bulkeley 2009; Leffel and Acuto 2018; Toly 2008) – show a considerable variation in meaning, especially regarding the members of such networks and their scope as they often include various “local” entities, like regions, or are mainly bilateral or regional (Acuto and Rayner 2016; Haupt and Coppola 2019). However, such analyses show developments of internationalisation without necessarily conceiving these networks as specific, unique actors in processes of global governance.

To assess what city networks are and how they contribute to global governance, we rely on a broad definition of global governance in IR research, defined as global “processes by which norms, rules, and programs are monitored, enforced, and adapted, as well as the structures in which they work”, and usually aimed to “achieve normatively laden political goals [… .]” (Zürn 2013, 408). Existent scholarship on global governance focuses on the interactions of different actors across different levels (e.g. Barnett, Pevehouse, and Raustiala 2022), but it also includes normative questions (Dingwerth and Pattberg 2006; Zürn 2018), focuses on power (Barnett and Duvall 2005) or provides historical perspectives (Steffek 2021). Cities and their networks have been a late addition to the set of actors linked to global governance (Weiss and Wilkinson 2022), oscillating between a new kind of global governors (Avant, Finnemore, and Sell 2010) or transnational actors (Risse 2013). However, analyses from a perspective on global governance are still missing, although many scholars identified a need for closer exchange between urban studies and IR to assess and explain the significance of cities and their networks in global governance (Herrschel and Newman 2017, 14–16; Ljungkvist 2014, 38). Acuto et al. (2021, 5) explicitly call for more systematic and comprehensive research beyond environmental politics and existing case studies. Secondly, they demand clarification regarding the role of cities, city networks, “the urban” and “the local” in international affairs. Finally, they encourage IR to locate cities and city networks conceptually and empirically in global governance.

In this article, we aim to close these gaps by focusing on the contributions of city networks to global governance, with a particular focus on global norms. Among the many outputs of global governance, norms – both as social practice but also as formal treaties – stand apart as standards of appropriateness (Finnemore and Sikkink 1998) that regulate specific normative problems from warfare and human rights to environmental politics through shared understandings of moral oughtness that addresses the behaviour of actors and creates social expectations (Jurkovich 2020; Winston 2018). This conceptualisation of norms opens different opportunities for engagement by ICNs as they may introduce themselves as new addressees for norms, support norms through implementation or even promote new norms. Existent scholarship on “norm dynamics” typically theorises and assesses actors, their different roles and activities linked to the emergence, diffusion, and implementation of norms (Finnemore and Sikkink 1998; Sandholtz 2017; Lantis and Wunderlich 2022). Thus, how ICNs engage in global politics can be assessed through their contributions to norm dynamics and how they position themselves in relation to global norms and their appropriateness. Taken together, we perceive an analytical focus on norm dynamics as an opportunity to ultimately support our theoretical and empirical knowledge of city networks and their interactions with other actors in different policy fields beyond environmental politics: If city networks engage in global norm dynamics, they are relevant for IR since they contribute to global governance.

To systematically distinguish between different network types and enable comparability, we suggest “cities” and “international” as central building blocks of a definition of international city networks, although both need some clarification: “City” is a multifaceted term that is often used interchangeably with “urban” or “municipal” and raises questions on whether it refers to population density, spatial or administrative boundaries (Kihlgren Grandi 2020, 3–6). Our understanding in this article refers to “cities” as administrative and governmental units, given that other definitions do not necessarily reflect the complex agency of cities (Acuto 2019; Bassens et al. 2019), especially their interest in networking with others on the national and international level. With regard to “networks”, we restrict ICNs to “multilateral” (Keohane 1990; Ruggie 1992) networks, excluding unilateral or bilateral forms (see Acuto and Leffel 2021, FN 1, 15). Accordingly, in this paper, we define ICNs as networks that consist of city members based in at least three countries, that may or may not include other types of actors, and whose focus can be on any given issue area of international relations. Since our units of analysis are ICNs and not specific cities, our analytical focus is on the international level throughout the article, although we acknowledge that linking the global to the city level is also relevant for global governance and IR.

In the following, we argue that research on global governance would profit from a better understanding of what ICNs are, how they are structured, what aims they pursue as their mission, how and whether their activities contribute to existing policies and, consequently, in what ways they are relevant for global politics. To advance conceptual, empirical, and comparative knowledge of ICNs in different issue areas, this article analyses a set of 30 networks that was systematically generated from an established and published list in urban studies (Tavares 2016, 15–26). We updated the information in this set and analysed several dimensions of these networks using multiple methods. In the first step, we provide a brief overview of existing findings on ICNs before we elaborate on our data and methods. Our analysis then starts with descriptive statistics on the structures of ICNs, evaluating publicly accessible data on membership, financing, and linkages to other actors in global governance to assess what ICNs are empirically. In the second step, we examine the aims of the networks by building on inductive categories derived from network mission statements. In a third step, we assess their relation to existing norms of global governance, analysing whether they adopt, modify, or even initiate global norms. These three dimensions provide a detailed picture of what capacities and support ICNs can have (structures), as well as what they declare as their mission (aims) and how they relate to existing norms in global governance (activities). All these factors are likely to influence the actual impact ICNs can have in global governance, an assessment required in future research and outlined in our conclusions. All in all, even the limited number of networks due to a restrictive definition of ICNs in our study shows a remarkable variance regarding structures, aims, and activities. However, we find that ICNs contribute noticeably to global governance, although further research is needed to explain their contributions and impact. To stimulate further research on city networks, we provide all of our data and analyses in the supplemental material of this article.

2. Existing research on international city networks and their contribution to global governance

ICNs are regularly analysed in urban studies, a multidisciplinary research programme where researchers from different disciplines, such as urban planning and development, political geography, sociology, and political science, but also IR and international law, examine urban phenomena, broadly conceived. Most analyses in urban studies share an analytical interest at the city level and thus assess the role of cities in global politics from a bottom-up perspective. Yet, cities and ICNs can also be analysed from perspectives more common in IR, which emphasise their contributions to global governance and theorise these actors as elements of global politics, rather than as international activities of specific local actors (Acuto 2013; Acuto and Rayner 2016; Gordon and Johnson 2017; Gordon and Ljungkvist 2022).

From a local perspective, cities and their networks today engage in a parallel form of diplomacy, so-called “city diplomacy” or “paradiplomacy” (Acuto and Rayner 2016; Kihlgren Grandi 2020; Tavares 2016). As international activities have become “an everyday practice for mayors, local government officials, and city bureaucrats” (Smith 2019, 143), many cities and local governments have established specific offices and strategies for their international affairs, signifying an administrative foundation for sustained international commitment (Acuto et al. 2018, 1; Ljungkvist 2014, 42). Such city diplomacy can take various forms, ranging from bilateral exchange with specific local, national or international counterparts to structured exchange among different members in ICNs. A main impetus for international activities is the collaborative exchange and policy learning, more effective local policy implementation, as well as interest representation (Bouteligier 2014, 67; Grønnestad and Nielsen 2022, 2958; Herrschel and Newman 2017, 74–75; Nijman 2016, 231). For example, cities hold conferences and summits, issue reports, start pilot programmes, and establish social media accounts, blogs, and newsletters (Acuto and Leffel 2020, 1762). They do so to exchange information, knowledge, and best practices with other cities, increase their capacities, and accelerate urban responses to common policy problems (Acuto and Rayner 2016, 1162).

The exchange among cities has given way to a growing formalisation and institutionalisation of network structures, transforming their initial collaboration into more complex governance arrangements (Davidson, Coenen, and Gleeson 2019, 697; Acuto and Leffel 2020, 1762). Over the last decades, ICNs have proliferated significantly and can be found across all continents and several policy fields (Acuto and Rayner 2016, 1153; Acuto and Leffel 2020, 2; Acuto et al. 2021, 15; Bouteligier 2013, 20–21). Research from urban studies assumes that these networks also enable urban influence on global politics (Bouteligier 2014, 58; Davidson et al. 2019, 3541; Ljungkvist 2014, 41): City networks interact with international organisations, attend international negotiations, and bring their ideas and concerns into the international realm (Acuto and Rayner 2016, 1161; Acuto et al. 2021, 1–2; Nijman 2016, 231–232). In particular, they have already shaped international sustainability and climate politics (Bouteligier 2014, 58; Smith 2019, 720), where the successful C40 network is often referenced (Acuto and Ghojeh 2019; Davidson, Coenen, and Gleeson 2019; van der Heijden et al. 2019). Still, city networks can be found across various policy fields: Analyses have listed around 70 per cent of city networks as “multi-issue networks” that engage in more than one global topic (Acuto and Rayner 2016, 1153). City networks pursue such involvement in global governance to further their interests and provide effective local governance (Acuto 2019, 136; Ljungkvist 2014, 32; Smith 2019, 134). Moreover, existing policies of international organisations and specialised agencies such as the EU, the WHO and UNESCO successfully offer incentives for cities to establish networks by increasingly recognising the importance of the urban level and including them in processes of global governance (Acuto et al. 2021, 1–2). The role of private investors, like philanthropies that support ICNs, is also assessed (Coppola and Haupt 2023; Davidson, Coenen, and Gleeson 2019).

Empirical analyses in urban studies show that cities and their networks implement global agreements and support global institutions at the urban level, most prominently regarding the Sustainable Development Goals (Kosovac, Acuto, and Jones 2020, 1) or climate politics and the Paris Agreement (van der Heijden et al. 2019). Studies have also found the support of ICNs for global health initiatives (Acuto, Morissette, and Tsouros 2017; Jakobi and Loges 2022), human rights (Oomen, Davis, and Grigolo 2016; Nijman et al. 2022), international migration policies (Oomen and Baumgärtel 2018; Durmus and Oomen 2022) and particularly the Convention on the Elimination of All Forms of Discrimination against Women (Och 2018; Runyan and Sanders 2021). City networks that implement global norms often present themselves as leaders, thus emphasising their alignment with global norms and underlining their willingness to pioneer new solutions or their ability to implement policies quickly (Acuto and Leffel 2020, 1768; Ljungkvist 2014, 48; Rapoport, Acuto, and Grcheva 2019, 4). Although the political activism of cities is not a zero-sum game at the cost of national politics, cities’ alignment with global policies can cause friction with national governmental politics that might oppose specific global goals (Smith 2019, 136; Acuto 2019, 135). The actual activities that cities can pursue internationally are also dependent on the national legal context and national politics: For instance, the Australian government has begun to assess city diplomacy against national foreign policy goals (Pejic and Acuto 2022), indicating that cities might be restricted with regard to the initiatives they take, although we find networking activities in most issue areas in global politics.

Although research on ICNs is a productive field that generates many important findings on their international activities, these studies are characterised by different approaches and varying empirical research interests, often leading to results mainly focusing on specific networks or specific issue areas. With a view to theoretical implications, the field currently lacks a systematic perspective that provides generalisable conclusions regarding ICNs’ contributions to global governance. In fact, existing studies raise empirical, conceptual, and methodological questions, in particular regarding the number and nature of ICNs: Acuto and Leffel (2021, 1759) refer to more than 300 networks with international activities, while other work (Acuto and Rayner 2016, 1148) analyses 170 city networks or 64 city climate networks alone (Cortes et al. 2022a, 3). So far, data is either not publicly available (Acuto and Leffel 2021; Acuto and Rayner 2016) or, if so, published only with regard to a specific issue area (Bansard, Pattberg, and Widerberg 2017; Cortes et al. 2022a). Other data is collected at the city level to analyse activities by members of climate networks (Heikkinen et al. 2020; Heikkinen, Ylä-Anttila, and Juhola 2019). Although some studies on environmental politics have analysed ICNs as networks (Cortes et al. 2022a; Haupt and Coppola 2019; Kern and Bulkeley 2009), they do not allow any conclusions beyond this field. This is complicated by the fact that many conclusions on ICNs in global governance are drawn from single-case studies (Acuto et al. 2021, 5). At the same time, if publications provide a larger picture of city networks and rely on descriptive statistics (e.g. Acuto and Rayner 2016), the underlying data remains often inaccessible. In sum, existent studies are of high value, but their variety often hinders comparisons and leaves us with neither a definite number of ICNs nor comparable information on membership and network development, but also on the instruments ICNs use to advance goals, and the issues they address.

From a perspective of global governance, these findings have significant implications but also beg further questions: International activities of ICNs challenge a state-centric international system and demonstrate the growing relevance of ICNs as new, subnational actors. ICNs represent a distinctive trans-local level in the multi-level system of global governance. Yet, we still need to gain more systematic knowledge of how ICNs typically interact with different actors, from national governments and non-governmental organisations to regional and international organisations or other ICNs. At the same time, existing research has often characterised ICNs as active transmission belts that transfer global norms to local places. This runs against established knowledge in IR that assigns a more comprehensive agency to any relevant actor in global governance – one that also comprises initiating change or criticising the status quo. While any attempt to systematise their structures, aims, and activities will remain challenging due to the sheer number and variety of ICNs, more detailed insights are needed to assess their core characteristics, role and significance in global governance in a comparative way.

3. Toward a systematic analysis of international city networks: data and methods

Our sample of thirty networks – analysed with multiple methods – is based on Tavares’ (2016, 15–26) list of more than 125 multilateral networks of subnational and urban actors, presented in his monograph on paradiplomacy (see also supplemental material). Although the list is not a recent overview, it remains the most detailed publicly accessible one in urban studies, as other large-N data on this issue have not been made public. It also presents long-existing city networks, increasing the relevance of its networks compared to any more recent sample. From this initial list, our online research revealed that thirty-one networks have since ceased to exist and were thus excluded from our sample. One network dissolved and, at the same time, was re-founded (in 2020), while another one came into operation through a merging of networks in 2015 – both were included in our data. To ensure similar coding procedures in our analyses, we excluded two city networks that only provided information in a language other than English. The remaining set included networks of different issue areas – from urban development to climate or security politics – and of a large variety of members. However, the list also contained networks of other, sub-state actors like federal states or specific (multinational) regions. These were eliminated according to our definition of ICNs. Following our definition, we excluded three networks in which cities were topics but not members, and one bilateral network consisting of cities only from the US and Canada. The remaining number of 30 networks is a significant reduction from the original list, yet it does not preclude findings on the variety of ICNs’ activities. Moreover, this reduction also signals the need for a coherent definition of ICNs in contrast to other, seemingly similar, networks of local actors.

For all the remaining 30 networks (see Box 1), we collected online data on their structures, aims, and activities. Specifically, we gathered online information (supplemented with information from email exchanges with networks in case of open questions) on the structure and organisation of these thirty city networks, particularly their founding year, number of members (including a ratio between cities as members and other actors within the network), and countries covered via city membership. Additionally, we analysed online information to determine whether the networks are single- or multi-issue and which issue areas are central. Also, we assessed whether networks report reliance on external financial resources (from corporations, civil society, international organisations, or public funds). Regarding their organisation, we collected data to distinguish between bottom-up and top-down networks (whether the cities themselves or international organisations started the networking initiative). Moreover, concerning the institutional complexity of city networks, we examined whether networks have specific organisational structures, like a secretariat or different internal governance units. We also collected information on the links city networks have to international organisations at the global or regional level in their operational work. In addition, we checked whether any of our networks have international governmental organisations as members, which was found not to occur at all in our sample.

Box 1. ICN Selected for Analysis in Alphabetical Order.

Table

Association of Cities and Regions for Sustainable Resource Management

Association of North East Asia Regional Governments

C40 Cities

Cities for Mobility

CITYNET

Climate Alliance

Energy Cities

Eurocities

European Association for Local Democracy

European Forum of Urban Security

European Land and Soil Alliance

FMDV – Global Fund for Cities Development

Global Covenant of Mayors for Climate and Energy

Ibero-American Center for Strategic Urban Development

International Association for Peace Messenger Cities

International Association of Educating Cities

Leading Cities

ICLEI – Local Governments for Sustainability

Mayors for Peace

MedCities

Metropolis

Organisation of Islamic Capitals and Cities

Organisation of World Heritage Cities

POLIS

Réseau Art Noveau Network

Resilient Cities Network

UNESCO Creative Cities Network

United Cities and Local Governments

World Energy Cities Partnership

World Smart Sustainable Cities Organization

Source: Own account.

The networks’ aims and activities were drawn from their mission statements, a source of idealised self-representation for internal and external audiences (Mizrahi-Shtelman and Drori 2021; Shibake et al. 2021). We identified these statements on network websites under titles like “About us”, “Our mission”, “Our vision”, or “Mission statement”. 20 networks had explicit mission statements, and a total of 25 had similarly themed, alternative, or supplementary documents. All the networks in our sample had at least the former or the latter type of documentation. Since mission statements are self-descriptive statements about principles and intended activities, they are an adequate source to explore the aims and activities of ICNs – even if these do not necessarily translate into policy change. The documents vary in length, from short paragraphs to several pages. In principle, this variation can lead to biases in the analysis that require further research into city networks’ missions. In our case, however, this risk is mitigated as we did not code to determine the extent to which networks pursue specific aims. We, therefore, coded either inductively (aims) or deductively (activities), considering the priorities of city networks foremost. The annexes of this article contain all documents, other sources, and information on each step of the qualitative and quantitative coding procedures.

All this data was combined into one data set that consists of statistical information and qualitative data (see Appendixes) to enable a first systematic and comprehensive assessment of the structures, aims, and activities of ICNs in global politics. To ensure reliability, a second coder checked all initial qualitative and quantitative coding. All conflicting codings were then re-checked by both coders and evaluated together for consensual interpretations. We also conducted some bivariate analyses, and some of these findings are presented in the text. Yet, while we see much potential in quantitative analyses, we are cautious regarding any over-interpretation of the results, given the low number of cases in our data. We discuss related questions in the conclusions.

4. International city networks and their contribution to global governance

Our empirical analysis focuses on ICNs’ structures, the aims they formulate as their missions, and their documented activities in relation to existing norms in global governance. By definition, ICNs in this article consist of city members of at least three countries, but their network structures might still vary from mainly governmental actors to multi-stakeholder groups in which cities are only some among many actors. This variance influences the comparability of ICNs to other actors in global governance. At the same time, focusing on what aims cities identify as their mission helps to overcome a potentially biased perception of city networks as functional networks of policy learning, and it opens up the possibility of perceiving them as international actors with a political agenda beyond managing local circumstances. The third dimension, activities in relation to existing norms, assesses whether ICNs are foremost adopting global norms – as often depicted in research on climate governance – or whether their political agenda also includes a modification or initiation of norms. The actual impact of ICNs on global governance remains outside the scope of this article. Nevertheless, these three dimensions allow a detailed assessment of the variety that IR research is confronted with, before attempting to measure influence. At the same time, network structure, network missions and relations to existing norms (as well as influence on global governance) might be related to each other.

4.1. The structures of ICNs

Even our limited number of 30 networks produces considerable variance in their structure. While the median number of members in our database is 199, some networks assemble several thousand members, with the largest network, United Cities and Local Governments, presenting more than 240,000 members. Other large networks are the Global Covenant of Mayors (more than 12,500 cities) and Mayors for Peace, with over 8,000 members. The smallest city network in our sample has only 10 members. At the same time, the term “cities” can be used quite flexibly: Some member cities of Mayors for Peace are, in fact, small towns with few inhabitants (e.g. in Luxembourg), while others are districts in larger cities (like sub-districts of Berlin). Given that competencies of mayors, municipalities, and cities vary between countries, these differences are to be expected. Yet, they result in considerable variance within and across networks, making comparisons difficult. On top of this, the number of countries in which cities are involved varies considerably: The most extensive network in terms of countries – Mayors for Peace – consists of cities from 166 countries and territories, while the smallest two networks each only assemble cities from seven countries. The median number of countries involved is 38, which still signifies an international structure that goes far beyond traditional bilateral partnerships of cities, and it supports the idea of ICNs as international, collective actors in global governance.

Our definition of ICNs includes the possibility that networks consist not only of cities but also of other types of members. 10 of our 30 networks consist only of cities, while the other networks have a varying membership base, some with nearly 90 per cent non-city members (missing data on four other networks). These actors can be public, private, or civil society, and the networks vary considerably concerning type and extent. From an IR perspective, this begs the question of whether cities are actually in the “driver's seat” of the activities of ICNs or whether they are an addendum to an already diverse set of multi-stakeholder networks. The influence of actors other than cities is also worth considering when analysing the funding structure: Of all ICNs analysed, the majority lists public funding as one among several financial sources (28 networks), while less than a third receive only public funds (eight networks). Civil society funding is mentioned by 18 networks, and corporate funding by 13. For example, the Resilient Cities Network is supported by the Rockefeller Foundation, the European Land and Soil Alliance is funded by membership fees of cities and associate members from civil society, and Eurocities receives funding from public, corporate and civil society sources, as well as from project funds and grants. The European Association for Local Democracy and the Réseau Art Nouveau Network are receiving most of their funds from the European Commission, while Cities for Mobility reports being predominantly funded by corporations. The specific amount of funding is usually unavailable, and how these funding structures impact the activities of city networks needs closer analysis (Coppola and Haupt 2023). At the same time, many city networks report linkages to international organisations – regional as well as global. Of all networks in our data set, 20 reported a linkage to regional organisations (13 of those referring to the EU), 18 reported linkages to one or more global organisations, and 13 reported linkages to both regional and global organisations. The EU plays a particularly prominent role in city networks, which might be explained by the availability of EU funds for regional development (Acuto and Leffel 2021). Nevertheless, the multiple links to global international organisations, either through funding and other support, but also as addressees of cities’ concerns, shows that ICNs typically have a global, rather than regional or local, outlook. This global perspective also concerns networks that emerged as bottom-up initiatives by members themselves (24 networks) and not only those initiated by international organisations (six networks). Still, networks’ relations to other actors and their specific activities require further research. The organisational level of networks also shows further variance that can be relevant for their activities: 27 networks have organisational structures like specific governance units, while 23 even have a formal secretariat. At the same time, the varying membership base and organisational characteristics raise the question of whether the idea of a network – rather than an “international association”, an “international trans-governmental organisation”, or an “international non-governmental organisation” – adequately reflects this type of actor in all cases.

Taken together, our analysis, which is based on a specific, restrictive definition of ICNs, still shows a large variance regarding membership, countries involved, funding, and organisational structures. Although variation in structural features is not uncommon for networks in global governance, it raises the question of to what extent ICNs – compared to other networks – form a distinct and unified category of actors with ICN-specific characteristics and effects and whether ICNs’ relevance is ultimately based on specific network features, less on the fact that they consist of subnational, urban actors.

4.2. The aims of ICNs

Our second step of analysis assesses what exactly ICNs pursue as their “mission”. For this purpose, we relied on an open, inductive coding that collected all aims mentioned in the data and combined them into six (non-exclusive) categories, namely “networking”, “exchange and learning”, “representation”, “internationalised orientation”, as well as “implementation”, and “leadership”.

The aim of “networking” includes not only cities but also extends to different actors, sometimes beyond formal network membership, like indigenous people, (municipal) experts, industry, practitioners, and international organisations. Mission statements often label these linkages to other actors as “(multi-stakeholder) partnerships”, “coalitions”, or “collaborations”, terms that are also applied to other forms of cooperation in global governance. At the same time, city networks often aim to foster “exchange and learning”, which includes sharing expertise, discussing training and capacity-building strategies and identifying best practices and lessons learned. These aims were also found within the majority of mission statements – 19 networks aim at networking beyond members, and 25 aspire to exchange and learn. This is in line with research in urban studies that emphasises the relation of city networking to administrative tasks of cities.

Yet, mission statements also refer to “representation”, aiming at complementing global governance with local input. Eight networks aim to elevate local voices in international forums and strive for better global visibility of urban concerns. The “internationalised orientation” found in 13 mission statements show that networks clearly communicate a perspective that reaches beyond urban borders. Of these, four networks exclusively mention the EU and its different bodies as addressees of their international outreach, while others refer specifically to the COPs in climate politics, to the UN, or more broadly to the global stage or the international agenda. Some networks explicitly address how their aims are to be realised at the international level, ranging from participation in conferences and meetings to advocating urban initiatives and scaling them up to the global level. Three networks explicitly mention their consultative status at the UN’s ECOSOC.

ICNs also refer to specific aspects of global governance that they want to support; the two categories of “implementation” and “leadership” represent important aims in mission statements: 12 networks explicitly aim to further the implementation of global policies that range from climate agreements to sustainability goals, human rights, and world heritage. In addition, eight networks aim to provide leadership in a given issue area of global governance, for example, by aspiring to “accelerate” political responses, to “go further and faster” than other actors, to “drive transformation”, or to function as “laboratories” for “innovation”. ICNs thus clearly aim “to lead” in global governance, often linked implicitly and explicitly to ideas of collective and local progress.

None of the networks mentions all of these six aims, but three networks refer to five of them: Mayors for Peace as one of the oldest networks in operation, United Cities and Local Governments as the largest network in our sample, and the European network Climate Alliance. In contrast, two networks only communicated one aim: With its goal of exchanging urban strategic thinking by establishing projects and sharing experiences or training practices, the Ibero-American Center for Strategic Urban Development falls within our category of “exchange and learning”. The Organisation of Islamic Capitals and Cities highlights its “internationalised orientation” by explicitly mentioning its general consultative status at ECOSOC, while otherwise focusing on specific urban aspects in its mission. Other ICNs focus only on internal aspects in their mission statements by declaring a combination of “networking” and “exchange and learning”; for instance, a regional network in North East Asia focuses on urban and regional development, and a network called Leading Cities works to connect cities and improve their resilience through technical support and exchange.

While findings from urban studies suggest that city networks regularly provide leadership through implementation (Bouteligier 2014; Och 2018), we only found the combination of “leadership” and “implementation” in four networks. Yet, as our findings show, ICNs regularly aim to implement substantive norms of global governance without identifying as leaders in a given issue area. At the same time, they claim “leadership” with regard to accelerating information exchange and learning among cities. All in all, this analysis of mission statements shows that ICNs formulate a diverse set of aims. Thus, they cannot be reduced to actors interested in local politics alone, nor are they focused only on other urban counterparts. Instead, many networks present their mission with an international orientation and explicitly relate to international organisations or global policies. From an analytical view, even our small sample shows that ICNs should thus not be reduced to urban actors but must be conceived as an integral part of global governance.

4.3. The activities of ICNs

Our last step analyses how ICNs relate to norms as central outputs of global governance. From an understanding of norms as “a standard of appropriate behaviour for actors with a given identity” (Finnemore and Sikkink 1998: 891), norms comprise standards based on non-codified social expectations and those derived from formal international treaties. More recent definitions (Jurkovich 2020; Winston 2018) highlight problem, value, oughtness, addressees, and behaviour as specific components of international norms. Thus, normative dynamics evolve when an issue in substance or procedure appears problematic in light of a specific value, creating expectations for actors to adapt their behaviour accordingly if that value represents an obligation due to a shared understanding of its normative oughtness. However, actors may also question this oughtness and dispute a norm's specific application or general appropriateness, resulting in processes linked to the initiation, diffusion, and implementation (Sandholtz 2017) but also to reactions like translation (Acharya 2004; Zimmermann 2017), contestation (Deitelhoff and Zimmermann 2020; Wiener 2018) or rejection (Acharya 2011; Schneiker 2021). To systemise what ICNs contribute to global norm dynamics, we reduced the existent variety to three distinct categories: “Adoption” is the explicit reproduction and support of current norms in global governance, “modification” is a critical assessment of current norms in global governance, and “initiation” is a more radical activity, rejecting current norms by presenting alternatives. In sum, since social and legal norms create collective expectations for actors but also enable opportunities for ICNs to engage in global politics, norm research allows us to grasp how ICNs position themselves against a normative status quo of different norms in global governance.

Our data shows that 20 out of 30 networks genuinely support current norms in global governance, even if these norms vary widely with regard to prominence and centrality in global governance: Eight networks explicitly name the SDGs, with five openly stating their backing of the Paris Agreement, and one claiming support of the IPCC and the broader “climate agenda”. In contrast, two other networks mention the New Urban Agenda and human rights, while one network mentions the World Heritage Convention. Even in our data, the majority of ICNs relate to environmental norms, which might suggest that this is the most prominent international issue area for cities.

At the same time, networks do not restrict themselves to a specific norm but often show support for multiple ones: For example, the Organization of World Heritage Cities expresses loyalty towards one specific agreement, the ICLEI (as a network on sustainability) explicitly states its support for a whole range of sustainability principles, while the International Association of Educating Cities expresses commitment to more than 10 norms, agreements, and institutions. Besides specific global norms or policies, we also find abstract support of concepts like “world peace” by the Association of North East Asia Regional Governments or “good governance” by the European Association for Local Democracy.

A more reformist understanding expressing a need to modify established substantial or procedural norms can be found in the mission statements of six networks. For example, the climate network C40 Cities aims at new forms of cooperation by building a broad coalition of actors under the umbrella of a Global Green New Deal. In contrast, the Climate Alliance tries to bring the rights and voices of indigenous people into the field of climate diplomacy by comparing it to governance arrangements regarding biological diversity, where the involvement of indigenous people is a long-standing norm. Both argue vocally for climate justice as a critique of current norms and principles of climate governance: “Since its founding, Climate Alliance has worked […] to strengthen the involvement and voice of indigenous peoples in the international climate process as well as in other key international processes such as the Convention on Biological Diversity” (Climate Alliance 2022, Advocacy).

Further examples of “modification” include institutional improvements, like the establishment of a board of “Mayors for Security” that the European Forum of Urban Security proposes, or it refers to rather abstract aspects of critique, like when the European Land and Soil Alliance argues for changing the forms of land consumption. Despite their critical impetus, almost all of these mission statements (five out of six ICNs) combine “modification” and “adoption”, clearly indicating adherence to existing norms and indicating that the aim for change is not intended to question current global governance and its norms radically.

Our sample only contains one ICN – Mayors for Peace – that clearly opposes current global governance principles in arms control. For several decades, the network has advocated for banning nuclear weapons, proposing a “culture of peace” as a new norm in international affairs and supporting the – only recently agreed upon and still marginal – Treaty on the Prohibition of Nuclear Weapons (Mayors for Peace 2021). These “initiation” activities thus explicitly reject the status quo and formulate a clear alternative to current norms on nuclear weapons. At the same time, the existent global nuclear taboo (Tannenwald 2007) – the widely shared expectation that nuclear weapons should not be used even if they are not formally forbidden – also means that such principled opposition is not a radical act. In contrast, the ICN takes up a critique many actors have on the existing possibility of nuclear war.

All in all, ICNs regularly aim to adopt substantive global norms, as often shown in urban studies. However, they cannot be reduced to an implementing role, as some also aim for normative change and even pursue alternative normative ideals. At the same time, they also put pressure on procedural norms: The fact that they engage in global politics at all must be regarded as a primarily implicit contestation of the state-centric international system and its practices.

4.4. Advancing the understanding of international city networks

Comparing networks and their characteristics results in a multifaceted picture that, while highlighting variance in what ICNs are and what they contribute to global governance, advances our understanding of ICNs nonetheless (Table 1): As networks, ICNs cooperate across borders with international and regional organisations but also with non-state actors like NGOs, businesses, or philanthropic organisations. Their self-proclaimed aims reflect missions concerning exchange and learning within the network but also include international, future-oriented missions of implementation and leadership or aspirations to represent urban interests at the global level. Regarding their activities, ICNs contribute to global governance by adopting specific global norms, but they also try to modify existing norms or initiate normative change in substantive and procedural terms. However, what ICNs are and what they do may be linked in different ways. Therefore, we present some findings on empirical linkages between the three dimensions that underline the potential of comparative analysis but also show the need for further research, particularly aiming at more conceptual and causal considerations.

Table 1. Results of analysing 30 international city networks.

Network Overview	Range	Median
Number of network members	10–240,000	199
Percentage of city members in network	11.39–100	87.28
Network founded in year	1980–2020	1994
Countries/Territories represented in network	7–166	38
Network Mission Articulation	Number	Percent
Document referring to missions	30	100
Networks with explicit mission statement	20	66.67
Alternative or additional documents	25	83.33
Network Membership	Number	Percent
Includes only city members	10	33.33
Includes other governmental members	17	56.67
Includes private members	9	30
Includes NGO members	10	33.33
Network Founding Initiative	Number	Percent
Networks initiated by city members (bottom-up)	24	80
Networks initiated by IOs (top-down)	6	20
Intra-Organisational Structure	Number	Percent
Networks with secretariat	23	76.67
Networks with multiple governance units	27	90
Reported Network Funding	Number	Percent
Networks report only governmental funding	8	26.67
Networks report funding from other sources	21	70
of which funding from IOs	8	38.10
of which funding from private actors	13	61.90
of which funding from civil society	18	85.71
Issues Addressed by Networks
Multi-Issue Network	15	50
Single-Issue Network	15	50
International Linkages of Networks	Number	Percent
Linkages to global IOs reported	18	60
Linkages to regional IOs reported	20	66.67
of which the EU is the regional organisation	13	65
Linkages to global and regional IOs reported	13	43.33
Explicit Aims of Networks	Number	Percent
Any aim	30	100
Networking	19	63.33
Exchange and learning	25	83.33
Representation	8	26.67
Internationalised orientation	13	43.33
Implementation	12	40
Leadership	8	26.67
Explicit Activities Related to Global Norms	Number	Percent
Adoption	20	66.67
Modification	5	16.67
Initiation	1	3.33
None of these explicit	10	33.33

Source: Own account.

Nonetheless, references to functional and inward-oriented aims predominate in quantitative terms: Most ICNs emphasise that they cooperate internationally to promote exchange and learning but consider networking to have its benefits. Thus, our results mirror debates in urban studies on the relevance of exchange, learning and networking (Acuto and Rayner 2016; Herrschel and Newman 2017). Internationalised orientation is a central aim for over 40 per cent of our networks, which also underlines a prominent aspect in the debate on ICNs in urban studies: ICNs actively reach out to the global level (Kosovac et al. 2021; Toly 2008). Our findings suggest that the extent of such an international orientation may be subject to structural features, in particular the size of these networks: Of the 13 ICNs that communicate an internationalised orientation, nine have a higher number of members than the median of all cases, and nine of these 13 also represent more countries or territories than the median. In turn, out of the 17 ICNs that do not explicitly refer to an internationalised orientation, 12 have a number of members lower than the median.

While existing studies regularly emphasise that ICNs engage in implementation, especially in environmental politics (Bouteligier 2014; Davidson, Coenen, and Gleeson 2019) or human rights politics (Och 2018; Oomen and Baumgärtel 2018), we found that only 12 out of 30 ICNs name implementation as central reason for their activism. Our findings indicate that international linkages to international or regional organisations or both may be essential for such an orientation: Out of 12 networks that aim to implement international agreements or policies, all have connections to international or regional organisations. Beyond this external dimension, our data also shows that three-fourths of those networks engaging in implementation have a secretariat, thus underlining studies that emphasise the importance of the internal organisation of ICNs for their international performance (Lecavalier and Gordon 2020).

Our findings on leadership justify reluctance concerning what can be expected from ICNs in global governance. Some conceptual work on cities in global governance might overestimate their influence (Barber 2013), while other studies regularly refer to leadership qualities, particularly related to environmental and climate policy (Bouteligier 2013; Davidson, Coenen, and Gleeson 2019). Other research has emphasised leadership as a rhetorical strategy of city networks (see, for example, Bansard, Pattberg, and Widerberg 2017) or suggested that this is primarily a strategic focus of specific, individual cities (Rapoport, Acuto, and Grcheva 2019). Our results show that only eight of the 30 ICNs in our sample explicitly refer to “leadership” when communicating their aims. All of them are essentially bottom-up initiatives, and 75 per cent engage in environmental politics, suggesting that the leadership narrative is primarily focused on a specific domain and may result from member cities’ interests and self-perception. At the same time, it also raises the question of who or what constitutes the reference point for leadership, asking whether some cities aim to lead in comparison to other cities or to national governments.

Finally, ICNs’ activities primarily support global norms by implementing them at the local level, but what they consider to be a normative point of reference differ widely from international, well-known treaties like the Paris Agreement or the unanimous UN SDGs to the New Urban Agenda that is only known to specialists (Hickmann 2021; G. da Silva 2018).

5. Conclusion: the relevance of ICNs for global governance

This article provided a comparative and systematic assessment of 30 ICNs, their structures and activities in global governance, supplementing existing case studies of ICNs. Our analysis resulted in four key findings: First, a prominent feature of ICNs’ network structures is not only the wide-reaching international urban networking, but these networks also bridge across different groups of state and non-state actors and different levels from the local to the global. Second, the purpose of ICNs is often networking and exchange among cities, but they cannot be reduced to this: Many of their mission statements refer to international norms and policies and express international dimensions far beyond problems at the urban level. Third, while this international orientation often implies that networks perceive themselves as tools for the local implementation of global norms, our analysis also shows that they aim to contribute in a more comprehensive way, often presenting the need for changing substantive norms of the international community. Finally, as our comparison shows, even when applying a restrictive definition of ICNs that focuses on cities as elementary members and a minimum of international linkages, these networks expose a remarkable variety of structures and activities.

Our article linked ICNs to norms because they are core building blocks of global governance; any activity targeted at modifying, initiating, or otherwise actively engaging with them signals a potential impact on global governance. Thus, if city networks engage in global norm dynamics, they are definitely relevant for global governance, even if their impact is likely to vary widely. Our article showed that ICNs engage in shaping and implementing different substantive norms. Yet, the relation of ICNs to substantive global norms can be more multifaceted than our typology suggests: What elements of norms are supported and which are being criticised also requires more analyses – given that this article shows that ICNs cannot be reduced to a role as implementers. The support of norms helps ICNs to integrate into the existing structures and processes of global governance. At the same time, such integration posits a challenge to procedural norms linked to global governance, given that ICNs embody a growing representation of (usually excluded) sub-national, urban actors at the global level. The fact that states sometimes restrict ICNs’ and cities’ international activities with reference to national foreign policy signals that the transformation of these procedural norms has consequences, even if they would be unintended.

The variety of ICNs suggests their importance for global governance may have structural conditions that warrant more attention in future research. This still requires a better comparative understanding of ICNs, including a better distinction from other multi-stakeholder networks and a closer examination of strategic processes and partnership selection of ICNs. While we analysed our initial data, we found several ICNs that ceased to exist. This “death” of ICNs only becomes transparent when analysing ICNs’ data comparatively and over a more extended period, and neither internal nor external conditions that contribute to the “death” of ICNs are examined in existing research. This leaves us with little information on what ICNs can “do wrong” despite a growing body of literature that emphasises their relevance and could profit from such information. At the same time, potential conflicts around ICNs also deserve more attention in research: The variety we found in their structures suggests that ICNs should not be treated as “black boxes” as they are not unitary actors: Their different members will bring in different perspectives and interests that could cause conflict or need moderation. Ultimately, ICNs should be assessed comparatively to understand the complex power relations between city members from the Global North and the Global South, or between the most relevant cities in the world economy and other cities (Leffel and Acuto 2018). Existing studies in environmental politics suggest an inclusive system of ICNs that provides support to local needs (Cortes et al. 2022b). However, findings from other issue areas indicate stratified structures in and between ICNs that mirror power relations between core and periphery (Leffel et al. 2023).

A closer perspective on conflict or complementarity could also examine whether a growing number of ICNs result in competing views on global norms or competition for resources, attention or other support. Such analyses would also include a more comprehensive picture of the strategic and practical relevance of these networks on the local or organisational level – in particular over time and given the competition that emerges from the fact that more and more ICNs exist that demand attention and other resources (e.g. Grønnestad and Nielsen 2022). Cities and other actors are likely to invest in those networks they deem to be “successful” or most relevant, but it is not obvious what characteristics – material or immaterial, global or local relevance – mark a “successful” network from that perspective. Also, “successful” ICNs that contribute to processes of global governance raise questions about the agency, legitimacy, and power of these networks. Further research could tackle conceptual questions of whether ICNs are developing their own agency in global governance, adding to an already long list of global governors (Hofferberth and Lambach 2022), or whether they indeed have a more transformative potential regarding a “rescaling” (Brenner 2014) towards local actors.

In sum, ICNs deserve multidisciplinary attention and assessments with multiple methods. While case studies are essential to understand how and with what specific effect ICNs integrate into global governance, comparative and large-N assessments could answer questions that emerge about structural preconditions for their impact but could also assess trends in ICNs’ engagement. Finally, urban engagement in global governance adds yet another layer to the already complex interrelation between the national and international levels, and the potential benefits, as well as resulting tensions, deserve more attention from all disciplinary perspectives.

Disclaimers

The research is part of a project on international city networks and global norms, funded by the German Research Foundation (DFG – funding number 468859403). The manuscript presents original work and has not been submitted elsewhere.

Acknowledgements

We thank the meeting participants of the German Political Science Association’s section on International Relations, especially Carmen Wunderlich and Tim Büthe for valuable comments. We would also like to express our gratitude to the editors and anonymous reviewers for their helpful feedback. All remaining errors are our responsibility.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Deutsche Forschungsgemeinschaft: [Grant Number 468859403].

Notes on contributors

Anja P. Jakobi

Anja P. Jakobi is Professor of Politics and International Relations at the University of Brunswick (TU Braunschweig, Germany). Her research focusses on global governance and international institution, in particular security and crime governance.

Bastian Loges

Bastian Loges is a senior lecturer at the Institute of International Relations at the University of Brunswick (TU Braunschweig, Germany). His research focuses on global norms and international institutions, with an emphasis on human rights politics.

Ronja Haenschen

Ronja Haenschen is a PhD researcher at the Institute of International Relations, University of Brunswick (TU Braunschweig, Germany). Her research interest lies at the intersection of International Relations and urban governance research, including diffusion theory, smart cities, and global governance.