This article will be published in volume 74, issue 1, "Urbanization in International Affairs," appearing in print in May 2022.
The past two decades saw the expansion of what we could call “global urban governance,” with urban issues sprawling across several multilateral sectors, as well as the thriving of “city diplomacy,” meaning the international relations of local authorities. Many actors in world politics embraced this expanded role for cities, but what about nation-states? With the continued influence of inward-looking nationalism and the enduring clout of many national governments on both domestic and international fronts, tensions between central and local executives might have surged to an all-time high. How could these discrepancies be resolved and what is the place of central-local relations in a time of global urban governance? Comparing how Australia and the United States have recently set out to manage the international engagements of local leaders, this essay offers a reflection on the importance of remembering the national politics of city diplomacy.
Cities across the globe are increasing their international engagement through bilateral relationships; national, regional, and transnational city networks; and direct involvement in multilateral processes. In a recent survey of 47 global cities, we found that 86 percent had an office dedicated to international engagement, often led by a chief city diplomat. The interplay of globalization and urban governance, foregrounded by rapid urbanization trends, have made it essential that city leadership take on increasingly international dimensions. As the Mayor of Bristol, Marvin Rees, put it recently, “When I was elected I did not come in with an intention to do lots of international work, [but] it has become increasingly apparent that you cannot deliver on a city level unless we are operating internationally.” This is now a common stance among mayors and municipal managers the world over, not just in major urban centers but also in mid-sized cities across the Global North and South. The centrality of cities to global challenges, and the push for city leaders to look and act beyond their jurisdictions in their everyday business, has again been demonstrated throughout the COVID-19 pandemic. In 2020, we witnessed city leaders collaborate transnationally on response strategies and share crisis management information, often in ways that contrast favorably with sluggish national responses.
This is no novelty. Over the past few decades, increasingly internationalist local governments seeking to expand their multilateral presence have found a counterpoint in nationalist central executives, which have been looking inward with a skeptical approach toward other countries. This is a critical tension that needs far more explicit and analytically systematic attention. Addressing this tension is especially needed due to the progressive expansion of what we could call “global urban governance” characterized by urban agendas and processes sprawling across several multilateral sectors, as well as what is now tagged as “city diplomacy.” This term entered the political science literature in the late 2000s in order to describe the international relations of local authorities, emerging from a linkage of practitioner interest (through city networks) and think tank research (from the Netherlands Clingendael Institute) as a background to the First World Conference on City Diplomacy in 2008. In spite of the now popular deployment of the term around climate action or migration, the original 2000s emphasis of these theoretical and policy developments was instead on the role of local governments in key security areas like conflict prevention, peace-building and post-conflict reconstruction.
Many actors in world politics embraced this expanded role for cities, but what about states? With the rise of populism and continuing clout of many national governments, tensions between central and local executives have surged to new heights on fraught policy issues like climate, migration, and pandemic response. Here we aim to begin addressing this gap by unpacking two recent examples of the evolving relationship between national and local governments, and the impact these have on city diplomacy and emerging regimes of global urban governance.
We begin with a call to revisit the well-established, albeit neglected, political scholarship on central-local relations, and do so from an explicitly diplomatic point of view. We then move to a comparison of the United States and Australia, two broadly analogous federal systems who in 2020 moved toward potentially divergent models of national governance of city diplomacy, and set them into a wider international context of shifting central-local relations. Such comparative analysis allows us to look beyond specific circumstances to identify common as much as divergent characteristics and potential emerging models of the national governance of city diplomacy. We use this “live” comparison of evolving central-local coordination as a launching point into tackling the above broader considerations. We argue for the need to consider central-local relations as critical components of city diplomacy and global urban governance processes. As city diplomacy evolves and systems of global urban governance become more institutionalized, it is natural that national governments will aim to maximize these diplomatic channels, while concurrently limiting the opportunities for foreign inference through subnational channels. While increasing national involvement in the realm of global urban governance has the potential to hinder city-led initiatives which are misaligned with broader national agenda, it also offers new opportunities for resourcing and expertise that could increase the relative importance and effectiveness of city diplomacy in overall foreign policy strategies.
Revisiting Central-Local Relations with a Global Urban Governance View
Over the past three decades, the way in which local authorities operate has progressively moved from localized managerialism to a more networked and globalized form of urban governance. This has cast the activity and external agency of cities into a multiscalar realm. City leaders now regularly interact, both formally and informally, with a host of agents and processes at the local, national, regional, and international levels. This evolving reality is further complicated by the emergence and proliferation of a variety of international urban actors like city networks, now numbering in the hundreds, trans-local urban coalitions of citizens and urban dwellers—not least the urban poor—as well as multinational business with explicitly “urban” interests and agendas.
Overt geopolitical motives, particularly those driven by national governments, rest uneasily with traditional narratives of city diplomacy. To date, city diplomacy has been largely characterized as transnational collaboration to address global issues where states have struggled to reach agreement, such as climate change, migration, and resilience. Putting aside somewhat utopic notions of “mayors ruling the world,” one distinct advantage that city leaders do enjoy over their national counterparts is less investment in geopolitical rivalries and traditional alliance structures. As Henri-Paul Normandin, the former Director of International Affairs at the City of Montreal and a longstanding Canadian diplomat, recently noted, “as a general proposition I would say that when we work with cities and mayors…we tend to be more pragmatic than ideological.”
While there is certainly truth to this characterization, Normandin also notes that city diplomats must remain “conscious” of geopolitics, which still impact city diplomacy and regimes of global urban governance in many ways. For example, the City of Taipei has developed bilateral relationships with over 50 cities and is an active member of major city networks such as United Cities and Local Governments (UCLG), Citynet, and the Asia Pacific Cities Summit. Given Taiwan’s limitations in engaging in multilateral systems, Taipei has used this international engagement to advance the interests of not only the city, but Taiwan more broadly. While Taipei promotes holism between city and state, the Israeli government has made attempts to encourage tourism to Tel Aviv and Jerusalem through a strategy that produces a “brand” for the cities divorced from the negative international connotations of the Israeli state. The relationship between national and global urban politics was also on display at the recent meeting of the Urban 20 (U20). Rather than having a secretariat, the hosting of the U20 has rotated between major global cities involved in the C40, UCLG, and ICLEI networks and based in the G20 host. In 2020, the G20 and U20 were scheduled to be held in Riyadh, Saudi Arabia, though both were convened virtually due to COVID-19. The event was held on the second anniversary of the death of journalist Jamal Khashoggi, and the mayors of London, Los Angeles, Paris, and New York boycotted the final summit due to human rights concerns in the host nation. Through the rapid expansion of city diplomacy, we have seen the evolution of global urban politics in real time. However, emerging scholarly efforts to make sense of these structural changes in urban and global governance have to some degree lost sight of the more localized dynamics at play, in favor of internationalist narratives. For instance, while international attention for the 2021 U20 meeting at the Italian G20 Summit again put emphasis on the international role of cities, this event was at the same time underscored by local political issues between the host cities, Milan and Rome, and taking place in the context of a domestic Italian politics characterized by ongoing tensions and an unstable central executive.
Scholarship in urban studies, particularly geography and planning, as well as in a proactive “urban” fringe of international relations, has attempted to conceptualize the shift in the locus of urban agency and the expansion of urban issues in global governance. This scholarship has explored, among other phenomena, the structural economic and historic factors leading to this evolution, the proliferation of city networking, broadening of city diplomacy, and the development of global urban governance across policy domains such as environment, migration, health, and security.  This is far from an exhaustive list, but provides a sense of the increasing activity and complexity of the intersection between urban and global governance processes, and the mounting scholarly interest in city diplomacy research across both camps. Yet, in spite of a well-rehearsed understanding of the “great divide” debate in international relations between the spheres of domestic and foreign policy,  as well as many local government studies addressing the interplay of state and city politics, one area that has received limited attention to date is how the relationship between national and local governments unfolds in respect to this diplomatic domain. Where this topic has been addressed it is often characterized as a preconceived narrative that pits “cities versus states,” where states represent stagnant political entities overcome by the quagmire of geopolitics and multilateral gridlock, while cities are progressive and responsive actors capable of addressing global challenges through purposeful transnational collaboration. Scholarship from political and urban geography has called for a more refined exploration of the historical “tango” of city and state power, and delved quite deeply into the rescaling and co-constitution of urban and state spatial politics under globalization. However, these accounts have largely been focused on longer-term macro evolutions of urban politics, and have offered little engagement with questions and theories of global governance and international affairs. There have also been some sophisticated attempts to understand these interactions as they relate to specific policy domains, for example the multi-level governance of migration or climate. Yet an explicit consideration of the impact of central-local relations on the “rise” of cities and debate on the urban age of multilateralism is scant at best.
This is not due to a lack of scholarship conceptualizing this complex relationship. Central-local relations historically animated much political science of the 1970s and 1980s, a time when local dynamics were tightly intertwined with the broader theorization of politics. In the final few decades of the 20th century, central-local scholarship also made an explicit engagement with issues of foreign policy. In fact, a central tenet of one of the milestones of international and diplomatic theory, Robert Putnam’s much-cited “two-level games,” comes exactly from this central-local perspective as infused with the attention to global governance we advocate for in this piece. Central-local relations also have a longstanding role in both more general discussions of local government law, as well as arguments that have sought to situate the city in relation to international legal considerations. In spite of limited debate, this relationship has not disappeared entirely from political science or some international affairs and area studies. For instance, the theme is still fertile ground for analysis of the subnational diplomatic dimensions and tensions in the People’s Republic of China and its growing megacities. It also receives recurrent discussion in policy and public administration venues like Local Government Studies, especially in relation to the United Kingdom, but also other Global North cases such as France, Germany, or the Scandinavian countries. Therefore, why do we aim to re-engage this debate and drive toward more domestic discussions of the expansion of city diplomacy?
In an era of increased “governance” and shifting purviews of government, especially with explicit pulls in academia and practice toward the global agendas emerging around cities, it becomes essential not to lose sight of the city’s continuing place within the nation. These calls and research traditions have been predominantly driven by interest in assessing, “local policy processes and outcomes within the context of a wide range of non-local factors and actors.” Yet the opposite direction of this narrative is equally valuable. If there is plenty of scholarship attending to the internationalization drivers affecting central-local politics, we call for a reverse perspective here, more explicitly speaking of global urban governance and city diplomacy within the context of domestic central-local processes. This, in turn, calls us to appreciate how the increasingly networked leadership of cities in a time of urbanization and globalization—partially interrupted as they may be by COVID-19—is driven by the “governance of complexity” and the convergence of domestic, local, transnational, and international political processes. Our approach also stresses, in a landscape where cities operate from within a range of multilevel governance regimes, the value of comparative considerations as launchpads for wider international relations assessments and theorizing. The goal of this point of view is not to argue that all cities, and all city diplomacies, are similar in their positioning. Rather, it is to stress the inherent and shared complexity of the “politics of urbanism,” as Canadian political scientist Warren Magnusson sought to describe it, that underpin how in an increasingly “urban” age it becomes more and more important to “see like a city,” in terms of scalar complexity and multilevel governance. We do so through a comparison of the United States and Australia.
Managing City Diplomacy in the United States and Australia: On Divergent Paths?
In the United States and Australia, we may now be witnessing the development of two divergent models of state-led city diplomacy. Despite a large disparity in relative global power, the countries share many similarities: both are federal, three-tier governmental systems, both enjoy high levels of income, and both have traditionally shared a broad alignment across many foreign policy areas as close allies.
In addition, both nations have local authorities who have been actively engaged in city diplomacy and demonstrated leadership in influential city networks. Due to Australia’s smaller population, this leadership has mostly been from its two major cities, Melbourne and Sydney (and to some extent Brisbane), while the United States is home to dozens of highly internationally engaged mid–large sized cities, alongside such major players as New York, Los Angeles, and Chicago. For example, the mayors of Melbourne, New Orleans, and Seattle are members of the C40 Cities Global Mayors COVID-19 Recovery Taskforce, which was rapidly convened in April 2020 through one of the most prominent transnational city networks to promote inclusive local pandemic response. Additionally, the mayors of Los Angeles, Austin, Boston, Chicago, Houston, Miami, New York, Portland, San Francisco, and Sydney were among the city leaders to endorse the group’s Statement of Principles. Melbourne, Sydney, Los Angeles, Chicago, Houston and New York have all been participants in the U20 initiative, which gathers major cities from Group of 20 member states who meet alongside the G20 to lobby and advocate for urban agendas to be taken into account within the formalized track of the G20 forum.
In 2020, the national legislatures of the United States and Australia both made moves toward greater federal government involvement in subnational diplomacy. In late 2019, the City and State Diplomacy Act was introduced into the U.S. Congress, a bill designed to harness and maximize the impact of international engagement by U.S. states and cities. This legislation has received bipartisan support in both the House and Senate. The Act proposes the creation of an Office of Subnational Diplomacy within the U.S. State Department to support the diplomatic efforts of subnational leaders and in its text recognizes the “increasingly significant” role that these actors are playing in U.S. foreign policy. Despite bipartisan support and passing the House in 2020, the passage of the Act is not assured. The key Republican sponsor of the bill in the Senate, David Perdue, lost his seat in the 2021 Georgia runoff election, and funding for the office was not included in the Senate version of the annual National Defense Authorization Act. However, the Act is significant in signaling a concerted effort to institutionalize subnational diplomacy and maximize its impact through the provision of national expertise and resources. Some members supporting the bill have characterized it as a necessity in order to match the well-developed subnational diplomacy of China, a threat which has also been identified by the former U.S. secretary of state.
The City and State Diplomacy Act presents a vision of city diplomacy which is inextricably intertwined with state-led diplomacy. It contends that it is in the U.S. national interest to “promote subnational engagements, align such engagements with national foreign policy objectives, and leverage federal resources to enhance the impact of such engagements.” It proposes the appointment of an Ambassador-at-Large for Subnational Diplomacy who is responsible for the coordination of federal support, identifying gaps in federal resourcing for subnational diplomacy, reporting to the secretary of state, and assisting in the development and implementation of subnational diplomatic engagements. The Act also creates a role for the State Department in identifying and supporting the enhancement of subnational diplomacy. The State Department first created a similar office under Hillary Clinton, appointing Reta Jo Lewis as Special Representative for Global Intergovernmental Affairs in 2010. This office was eventually folded into the Bureau of Public Affairs and ultimately discontinued. Later in the Barack Obama administration, Ian Klaus operated as a Senior Advisor for Global Cities within the State Department, a role which has also since been dissolved. Recently, there have been calls for greater institutionalization of this function through the City and State Diplomacy Act.
In terms of broader central-local relations in the United States, we may also be witnessing a policy shift caused by the transition from the Donald Trump to Joe Biden administrations. The Trump administration was characterized by limited interaction between mayors and the federal government and significant animosity from the president toward sanctuary cities. This included attempts to withhold federal funding from cities who supported the sanctuary movement. We saw a number of attempts of U.S. city leaders to act collectively in spite of national policy, for example through the “We Are Still In” campaign of cities and other local and state actors to remain committed to the Paris Agreement goals after U.S. withdrawal, or through the collective call of U.S. cities to participate in the development of the Global Compact for Migration after Washington withdrew from the negotiations. During the transition phase the Biden administration signaled its intent to work more closely with city leaders on a number of critical challenges. President-Elect Biden and Vice President-Elect Kamala Harris met with the U.S. Conference of Mayors in November 2020 and promised collaboration and an open approach to federal–local relations under the new administration. It remains to be seen in what form this collaboration will take, but the potential introduction of the City and State Diplomacy Act means it may extend to international engagement. Should the Act not pass Congress, the administration could still explore other avenues through executive action to more directly engage cities in its domestic and foreign policymaking.
In contrast to the U.S. model, the federal government in Australia has recently embarked on an effort to centralize foreign policy under national control. In late 2020, the government introduced and quickly passed the Australia’s Foreign Relations (State and Territory Arrangements) Bill 2020. This legislation sets up a regime where public entities in Australia, including state and local governments and public universities, must report all arrangements they make with foreign entities, including foreign national, state, and local governments and government-controlled universities. The Australian federal government has the opportunity to review these arrangements and unilaterally cancel them if they are deemed to be incongruent with “Australia’s foreign policy.” This legislation is widely understood to be in response to the decision of the Victorian Government, one of Australia’s state governments, to sign a memorandum of understanding with the Chinese government regarding the Belt and Road Initiative. Indeed, while Senator Henderson contended in the second reading of the Bill in the Senate that it is “not focused on any particular country,” the Senator’s initial speech on the legislation stated as its first example that, “This Bill means, I believe, the end of the road for the Victorian Government’s Belt and Road Initiative (BRI) agreement with China.” Additionally, the federal government included public universities within this framework, as they have had long-running concerns over foreign interference in Australian academic institutions. The public Senate Inquiry into the Bill was dominated by discussion of China and included submissions from a number of groups and individuals who have publicly warned of Chinese foreign influence in Australia.
The new Australian bill approaches subnational diplomacy, including city diplomacy, from an intent to monitor and control foreign relations and minimize the risks of foreign interference through subnational channels. It is based on the premise that the federal government has “exclusive responsibility” for Australia’s international relations, while the City and State Diplomacy Act contends that the federal government has “primary” responsibility for diplomacy. Although this is a widely accepted position in Australia, it has some constitutional legal ambiguity in the federation. As opposed to the City and State Diplomacy Act, the bill itself makes no reference to the potential benefits of subnational foreign arrangements and does not explicitly include provisions for supporting subnational entities in conducting foreign relations. The public inquiry regarding this bill demonstrated that the Australian Government and its Department of Foreign Affairs and Trade (DFAT) currently have limited information on the foreign arrangements that local governments in Australia have, or the diplomatic activities they are conducting. DFAT currently has no section dedicated to urban affairs or direct institutional link with local governments. Although the federal government does have a minister for population, cities and urban infrastructure, this portfolio is focused on domestic matters. Historically, there have been few institutional linkages between federal and local governments in Australia, the most prominent being through the Council of Australian Governments (COAG).
COAG was the peak governmental organization in Australia, which included membership of the Prime Minister, state premiers, and the President of the Australian Local Government Association (ALGA). The group, which met twice yearly, provided an avenue for local government to directly provide input into national policymaking and was recognized in the 2020 UN-Habitat global report as an example of institutional multilevel governance. As COVID-19 began to impact Australia, however, the Prime Minister convened a new, leaner national group aimed at rapid response, without local government representation. It was subsequently decided that this National Cabinet would replace COAG. There is currently a process underway to determine how the full range of COAG committees will integrate with the National Cabinet, and the ALGA will retain some linkages with the new architecture—but not as a primary member of the cabinet. It remains to be seen whether the role of the ALGA will be diminished in this new structure. Regardless, there remains no central-local coordination on the international engagement of cities and the new foreign relations legislation does not appear aimed at addressing this omission. The Bill places the onus on local governments to report all their international arrangements, and current budgetary allocations for DFAT appear focused on the development of a public register and review of these and other subnational agreements, as opposed to the allocation of federal resources to support city diplomacy in the U.S. City and State Diplomacy Act.
Time will tell how these arrangements evolve, likely at the behest of shifting domestic politics as the Biden administration gets underway and the upcoming Australian federal elections approach. However, this juxtaposition already offers a preliminary distinction as to two modes of institutionalizing city diplomacy. While both models aim to minimize policy inconsistency between the foreign relations of sub- and national governments, the U.S. approach appears more intent on promoting collaboration and harnessing the potential of subnational diplomacy to enhance U.S. foreign policy, whereas the Australian model aims to centralize, monitor, and tightly control this engagement. It is of course possible that in practice, both models would lead to overarching federal control, with U.S. municipalities increasingly dependent on national resources and expertise. The operationalization of the Australian legislation is at the discretion of the minister for foreign affairs, meaning the intensity of the oversight will likely vary between ministers. Notably, in both states the impetus for reforming approaches to subnational diplomacy appear partly driven by concerns over geopolitical rivalry with China. The methods proposed for addressing these threats are divergent, however, and in some ways reflect the broader foreign policy approaches of both nations. As a middle power in the Asia–Pacific region, Australia maintains a defensive stance toward China and has reacted strongly to threats of foreign interference; however, it must also weigh this aggression against its reliance on China as its premier trade partner. Relations between the states have recently deteriorated, in part due to accusations of foreign interference, including those made during the Senate Inquiry into its foreign relations bill and a concurrent inquiry into multiculturalism in Australia. Conversely, given the economic and political power of the United States, its approach to city diplomacy projects a confidence in the capacity of U.S. cities and states to purposely project their soft power internationally, in a way that supplements state-led foreign policy. Here there is greater recognition of the effectiveness of Chinese city diplomacy through its local government Foreign Affairs Offices and a desire to “meet or beat China at its own game,” through coordinated multilevel U.S. diplomacy.
At the outset of 2021, central-local dynamics seem as directly intertwined with city diplomacy as ever. As ours is very much a live comparison of how the situation has been evolving in the United States and Australia, and we are yet to see the impacts of these two emergent paths, we must be cautious in overextending the conclusions that can be drawn at present. However, the comparison does provide an opportunity to reflect on the potential changes we may witness in city diplomacy and global urban governance if national governments are to increase their direct engagement in the international relations of local authorities. While transnational city networking has grown exponentially over the previous few decades, to date, national governments have provided limited resources for these activities, which have traditionally been supported by multilateral organizations, regional organizations such as the European Union, and philanthropies. Opinions as to the value and viability of city diplomacy vary substantially both among countries and between those of different political persuasions in the same countries. To some extent we have seen a saturation of networks in pressing global policy areas such as the environment, as well as competition for scarce funding and engagement from cities whose limited international resources are being stretched thin. Direct engagement and resourcing of city diplomacy by national governments, as is tentatively proposed by the City and State Diplomacy Act, offers an opportunity to significantly increase the scope and effectiveness of this engagement. National support also offers the opportunity for city diplomats to benefit from the expertise and experience of their national counterparts, a notable advantage as cities have identified a lack of training for their staff in conducting diplomatic activities. It is also likely to have real implications for multilateralism. As states remain the indispensable interlocuters of the international system, greater coordination between national and city governments is likely to lead to more opportunities for cities to directly engage in multilateral fora, such as we saw during the development of the Global Compact on Migration.
National involvement in city diplomacy is, however, a double-edged sword. Access to greater local legitimacy and resourcing could come at the cost of municipal independence and the need for city leaders to more earnestly navigate concurrent national and geo-politics. In essence, cities may be constrained by playing their own “two-level game.” We already see this in Australia, with the primary intent of the legislation being to limit avenues for foreign interference and eliminate foreign policy inconsistency between levels of government. The over 90 Sister City arrangements that Australian local governments have with Chinese cities came under scrutiny during the Senate inquiry into the legislation, especially in light of recent political tension between the nations, and these will undoubtedly be a focus of the government’s new review mechanism. It is likely that national government involvement in city diplomacy will limit the capacity of local leaders to push ahead of their states in pursuing progressive agendas and minimize the productive tensions we currently see in central-local relations. This will be exacerbated if cities become reliant on national funds and expertise to resource their international engagement activities.
A fuller appreciation of this evolution of city diplomacy and global urban governance would benefit from a broader systematic comparative analysis that takes account of central-local relations as they pertain to international urban engagement across the Global North and South. Although this analysis is beyond the scope of this article, setting comparisons like ours into a wider context of experiences might yield greater insights. For example, consider these developments in the context of China’s highly developed and often controversial subnational diplomacy, or France’s bottom-up advocacy, the weak municipalism characterizing much of India, or indeed the city dependency of weak federal and national systems like those of the Arabian Peninsula and some of Latin America. Additionally, there is potential for further examination at the impact of supranational entities such as the European Union, who have directly supported a range of transnational urban initiatives on central-local relations, particularly in the context of contested nationalist politics on the continent. Drawn systematically, these parallels and conversations would present fertile ground not just for further comparative research but also for tangible policy exchange and for a more domestically savvy city diplomacy discussion. Equally, how the politics of central-local relations are operationalized in different political systems, democratic and non-democratic, presents further variables for analysis and practice. As the planet increasingly urbanizes and networks of cities become more transnationally connected through multiscalar forms of global urban governance across a breadth of policy domains, we are more likely to see national governments become involved in the international engagement of their cities, whether through efforts to support or control it. City diplomacy is likely to become more closely intertwined with the broader multilevel foreign policy strategies that states employ, as opposed to subordinated to an alternative “track.” Whether this will subvert the traditionally progressive goals of city leaders or enhance their international and domestic impact remains an open question.
 Anna Kosovac, Kris Hartley, Michele Acuto, and Darcy Gunning, “City Leaders Go Abroad: A Survey of City Diplomacy in 47 Cities,” Urban Policy and Research 39, no. 2 (February 2021): 127–142.
 Nicholas Phelps, and Julie T. Miao, “Varieties of urban entrepreneurialism,” Dialogues in Human Geography 10, no. 3 (2020): 304–321; Kathryn Davidson, Lars Coenen, Michele Acuto, and Brendan Gleeson, “Reconfiguring urban governance in an age of rising city networks: A research agenda,” Urban Studies 56, no. 16 (2019): 3540–3555.
 Perry World House, Bristol and beyond: A Mayor on the World State with Marvin Rees, Mayor of Bristol, United Kingdom (Philadelphia, PA, November 24, 2020), https://www.youtube.com/watch?v=ShJn4fXHLiw.
 Anna Kosovac and Daniel Pejic, “What’s next? New Forms of City Diplomacy and Emerging Global Urban Governance,” in Cities in Global Governance: From Multilateralism to Multistakeholderism?, ed. Agustí Fernández de Losada and Marta Galceran (Barcelona: CIDOB, 2021).
 Noah Toly, “Brexit, global cities, and the future of world order,” Globalizations 14, no. 1 (2017): 142–149.
 Michele Acuto, “Engaging with global urban governance,” in Doing Global Urban Research, ed. John Harrison and Michael Hoyler (London: Sage, 2018): 96–109.
 Michele Acuto, “City diplomacy,” in The SAGE Handbook of Diplomacy, eds. Costas M. Constantinou, Pauline Kerr, and Paul Sharp (London: SAGE, 2016): 510–520; Lorenzo Kihlgren Grandi, City Diplomacy (London: Springer Nature, 2020).
 Rogier Van der Pluijm and Jan Melissen, City diplomacy: the expanding role of cities in international politics (The Hague: Netherlands Institute of International Relations “Clingendael,” 2007).
 Michele Acuto, Anna Kosovac, and Kris Hartley, “City Diplomacy: another generational shift?,” Diplomatica 3, no. 1 (March 2021): 1–10.
 Davidson et al., “Reconfiguring urban governance.”
 Sohaela Amiri and Efe Sevin, eds., City Diplomacy: Current Trends and Future Prospects (Cham: Palgrave Macmillan, 2020).
 Benjamin R. Barber, If Mayors Ruled the World: Dysfunctional Nations, Rising Cities (New Haven: Yale University Press, 2013).
 Perry World House, “Cities in a New Era.”
 Kosovac et al., “City leaders go abroad.”
 Rhys Crilley and Ilan Manor, “Un-Nation Branding: The Cities of Tel Aviv and Jerusalem in Israeli Soft Power,” in City Diplomacy: Current Trends and Future Prospects, ed. Sohaela Amiri and Efe Sevin (Cham: Palgrave Macmillan, 2020): 137–60.
 Helmut Philipp Aust and Anél Du Plessis, eds. The Globalisation of Urban Governance (London: Routledge, 2018).
 Simon Curtis, “Global Cities as Market Civilisation,” Global Society 33, no. 4 (2019): 437–61; Michele Acuto and Benjamin Leffel, “Understanding the Global Ecosystem of City Networks,” Urban Studies, online first, July 7, 2020, available at: https://doi.org/10.1177%2F0042098020929261; Ian Klaus, “The State of City Diplomacy,” Urbanisation, online first, May 21, 2020, available at: https://doi.org/10.1177%2F2455747120913186; David J. Gordon, Cities on the World Stage: The Politics of Global Urban Climate Governance (Cambridge, United Kingdom; New York, NY: Cambridge University Press, 2020); Barbara Oomen, “Decoupling and Teaming up: The Rise and Proliferation of Transnational Municipal Networks in the Field of Migration,” International Migration Review 54, no. 3 (2020): 913–939; Michele Acuto, Mika Morissette, and Agis Tsouros, “City Diplomacy: Towards More Strategic Networking? Learning with WHO Healthy Cities,” Global Policy 8, no. 1 (2017): 14–22; Kristin Ljungkvist, “Toward an Urban Security Research Agenda in IR,” Journal of Global Security Studies 6, no. 2 (2021): 1–17.
 Acuto et al., “City Diplomacy: another generational shift?”.
 Ian Clark, “Beyond the great divide: Globalization and the theory of international relations,” Review of International Studies 24, no.4 (1998): 479–498. Of course this presumably “hard” separation has been thoroughly questioned and recast in international theory, and yet it still holds significant purchase in the practice of statecraft across most nation states today. See Rob B.J. Walker, Inside/outside: international relations as political theory (New York: Cambridge University Press, 1993).
 Simon Curtis, ed. The power of cities in international relations (London: Routledge, 2014).
 Barber, If mayors ruled the world.
 Peter J. Taylor, Extraordinary Cities: Millennia of Moral Syndromes, World-Systems and City/State Relations (Cheltenham: Elgar, 2013).
 Neil Brenner, New State Spaces: Urban Governance and the Rescaling of Statehood (Oxford; New York: Oxford University Press, 2004).
 Tiziana Caponio and Michael Jones-Correa, “Theorising Migration Policy in Multilevel States: The Multilevel Governance Perspective,” Journal of Ethnic and Migration Studies 44, no. 12 (2018), 1995–2010; Michele M. Betsill and Harriet Bulkeley, “Cities and the Multilevel Governance of Global Climate Change,” Global Governance: A Review of Multilateralism and International Organizations 12, no. 2 (2006): 141–60.
 R. A. W. Rhodes, “Some myths in central-local relations,” Town Planning Review 51, no. 3 (1980): 270–285; and R. A. W. Rhodes, Control and power in central-local government relations (London: Routledge, 2018).
 Robert D. Putnam, “Diplomacy and domestic politics: the logic of two-level games,” International Organization 42, no. 3 (1988): 427–460.
 Gerald E. Frug, “The Central-Local Relationship,” Stanford Law & Policy Review 25, no. 1 (2014): 1–20.
 Yishai Blank, “City Speech,” Harvard Civil Rights-Civil Liberties Law Review 54, no. 2 (2019): 365–380.
 Mingjiang Li, “Central-local interactions in foreign affairs,” in Assessing the balance of power in central-local relations in China, ed. John Donaldson, (London: Routledge, 2016): 209–232.
 Vincent Béal and Gilles Pinson, “From the governance of sustainability to the management of climate change: Reshaping urban policies and central-local relations in France,” Journal of Environmental Policy & Planning 17, no. 3 (2015), 402–419.
 Martin Laffin, “Central-local relations in an era of governance: Towards a new research agenda,” Local Government Studies 35, no. 1 (2009), 21–37.
 Laffin, “Central-local relations in an era of governance,” 21.
 Roger Keil, “Globalization makes states: perspectives of local governance in the age of the world city,” Review of International Political Economy 5, no. 4 (1998): 616–646.
 Warren Magnusson, Politics of Urbanism: Seeing Like a City (London and New York: Routledge, 2013).
 C40 Cities, “The Global Mayors COVID-19 Recovery Task Force,” https://www.c40.org/news/global-mayors-covid-19-recovery-task-force/. (accessed January 8, 2021).
 U.S. Congress, House, City and State Diplomacy Act, H.R.3571, 116th Cong., 1st sess., introduced in House June 27, 2019, https://www.congress.gov/bill/116th-congress/house-bill/3571.
 Anthony F. Pipa, and Max Bouchet, “Partnership among Cities, States, and the Federal Government: Creating an Office of Subnational Diplomacy at the US Department of State,” Brookings (blog), February 17, 2021, https://www.brookings.edu/research/partnership-among-cities-states-and-the-federal-government-creating-an-office-of-subnational-diplomacy-at-the-us-department-of-state/.
 Catherine Putz, “A Discussion with US Senator Chris Murphy about Subnational Diplomacy and China,” Diplomat, September 9, 2020, https://thediplomat.com/2020/09/a-discussion-with-us-senator-chris-murphy-about-subnational-diplomacy-and-china/.
 Michael R. Pompeo, “U.S. States and the China Competition,” National Governors Association Winter Meeting, Washington, D.C., February 8, 2020, https://2017-2021.state.gov/u-s-states-and-the-china-competition/index.html.
 U.S. Congress, City and State Diplomacy Act.
 Pipa and Bouchet, “Partnership among Cities, States, and the Federal Government.”
 Benjamin Leffel, Reta Jo Lewis, Corey Jacobson, Luis Renta, and Kevin Cottrell, “It Is Time for the United States to Institutionalize Subnational Diplomacy,” German Marshall Fund of the United States (blog), January 26, 2021, https://www.gmfus.org/news/it-time-united-states-institutionalize-subnational-diplomacy.
 Miriam Enriquez and Sozi Pedro Tulante, “The Sanctuary Cities Debate Explained,” (Philadelphia, PA: Perry World House, University of Pennsylvania) May 28, 2020, https://global.upenn.edu/perryworldhouse/news/sanctuary-cities-explained.
 Colleen Thouez, “Cities as Emergent International Actors in the Field of Migration: Evidence from the Lead-Up and Adoption of the UN Global Compacts on Migration and Refugees,” Global Governance: A Review of Multilateralism and International Organizations 26, no. 4 (23 November 2020): 650–72.
 Kristin Musulin, “Biden Promises Support, Collaboration with US Mayors,” Smart Cities Dive, November 24, 2020, https://www.smartcitiesdive.com/news/president-elect-biden-promises-support-us-conference-mayors/589608/.
 Australian Government, “Australia’s Foreign Relations (State and Arrangements) Bill 2020.”
 “Second Reading, Australia’s Foreign Relations (State and Territory Arrangements) Bill 2020,” Senator the Hon. Sarah Henderson (blog), November 30, 2020, https://sarahhenderson.com.au/second-reading-australias-foreign-relations-state-and-territory-arrangements-bill-2020-30-november-2020/.
 “Foreign Relations Bill Safeguards Australia’s National Interest,” Senator the Hon. Sarah Henderson (blog), August 27, 2020, https://sarahhenderson.com.au/foreign-relations-bill-safeguards-australias-national-interest/.
 Prime Minister of Australia, “Ensuring a Consistent Australian Foreign Policy,” Prime Minister of Australia, August 27, 2020, https://www.pm.gov.au/media/ensuring-consistent-australian-foreign-policy.
 U.S. Congress, City and State Diplomacy Act.
 Brian R. Opeskin, “The Role of Government in the Conduct of Australia’s Foreign Affairs,” Australian Year Book of International Law Online 15, no. 1 (1 January 1994): 129–53.
 United Nations Human Settlements Programme (UN-Habitat), World Cities Report 2020 (Nairobi, Kenya: UN-Habitat, 2020).
 Daniel Hurst, “Eric Abetz Refuses to Apologise for Demanding Chinese-Australians Denounce Communist Party,” Guardian, October 15, 2020, http://www.theguardian.com/australia-news/2020/oct/16/eric-abetz-refuses-to-apologise-for-demanding-chinese-australians-denounce-communist-party.
 Daniel Pejic, Michele Acuto, and Anna Kosovac, “Tracking the Trends in City Networking: A Passing Phase or Genuine International Reform?” Perry World House, University of Pennsylvania, September 2019, http://bit.ly/38VOeQ5.
 Kosovac et al., “Conducting city diplomacy.”