Every August, the mayors of Hiroshima and Nagasaki reaffirm their commitments to peace and eliminating nuclear weapons through annual commemorations of the atomic bombings. Currently, city leaders around the world–– including many in the U.S.––are deeply engaged in addressing global challenges such as climate change, migration and refugee crises, and pandemics. Yet the pathways for these same leaders to participate in security and defense policies, like nuclear policy, are less clear and scarcely explored. 

Nuclear weapons policy is generally considered a prerogative of national governments. Consequently, the legitimacy, and effectiveness, of global diplomatic efforts by the mayors of Hiroshima and Nagasaki have at times been questioned.¹ Yet, these leaders are among the only ones consistently practicing city diplomacy for nuclear weapons policy. 

Anchored in painful memories of the atomic bombings, or what we call “nuclear legacies,” the mayors of Hiroshima and Nagasaki have traveled the world with local hibakusha (atomic bomb survivors). Collectively, they have spoken to an international audience about the loss of numerous lives in their cities, as well as the long-term, ongoing harm caused by radiation exposure stemming from the detonations of the atomic bomb. Together they have called attention to the inhumanity of nuclear weapons as a lived reality, not just an abstract threat. 

In 1985, the mayors of Hiroshima and Nagasaki established what is now known as Mayors for Peace, a coalition of cities dedicated to advocating for peace and nuclear abolition, based on these specific nuclear legacies. Mayors for Peace has since become one of the largest city networks in the world, with more than 8,000 member cities. This form of civic engagement for their affected communities extends beyond the bounds of their municipalities and even their national borders, and has firmly established a place of the appeals for peace from Hiroshima and Nagasaki within the UN frameworks for nuclear disarmament negotiations

The mayors of Hiroshima and Nagasaki’s international advocacy and participation are key examples of city diplomacy as it relates to nuclear policy; they demonstrate how local nuclear legacies are inherently tied to international security policies and how acknowledging nuclear legacies can be a powerful tool for global civic action. For city diplomacy to gain a foothold in nuclear policy, it is necessary to find clear ways for city leaders to participate in global policy debates alongside national governments. 

Building on the examples of Hiroshima and Nagasaki, we argue that U.S. city leaders can define pathways for city diplomacy in nuclear policy by acknowledging ubiquitous local nuclear legacies; taking legislative actions addressing these specific nuclear legacies; and actively participating in global nuclear policymaking through the UN framework of the Treaty on the Prohibition of Nuclear Weapons (TPNW), which entered into force in 2021. We define nuclear legacies as the past and ongoing impacts of nuclear development, testing, deployment, and policy on communities, individuals, and environments. 

[The mayors of Hiroshima and Nagasaki] demonstrate how local nuclear legacies are inherently tied to international security policies and how acknowledging nuclear legacies can be a powerful tool for global civic action.

Nuclear legacies exist throughout the U.S. and many municipalities acknowledge them. Approximately 80 U.S. cities and towns, as well as six U.S. states, have passed resolutions calling on the U.S. Federal Government to prioritize and take concrete steps towards nuclear disarmament. Some even support the ultimate goal of eliminating nuclear weapons. Most of these resolutions are the result of the Back from the Brink campaign² and include references to specific local nuclear legacies. 

The substance of these resolutions widely align with the spirit and objectives of the TPNW, especially the treaty’s commitment to pursuing nuclear justice enshrined in Articles 6 and 7. At least 51 of the 64 resolutions that we analyzed explicitly draw from and support the TPNW as a framework for their own stance on nuclear weapons. Many resolutions also implore the federal government to sign onto the treaty. 

The TPNW prohibits the development, testing, production, and use of nuclear weapons. It recognizes the deeply concerning nature of nuclear weapons development, including the extreme risk that their accidental or intentional use could have on “human survival,” public health, the environment, socioeconomic development, and the global economy reaching into posterity. Significantly, on page one of its preamble, the TPNW directly names the “unacceptable suffering of and harm caused to the victims of the use of nuclear weapons (hibakusha), as well as those affected by the testing of nuclear weapons” and recognizes “the disproportionate impact of nuclear-weapon activities on indigenous peoples.”³

The preamble to the TPNW applies an intersectional frame to disarmament by recognizing the disproportionate impacts of nuclear weapons on women and girls and Indigenous peoples, land, and cultures. As such, the TPNW incorporates gender and indigeneity into discussions of the stakes of nuclear disarmament, contributing feminist, anti-racist, and decolonial perspectives to the topic. Its Articles 6 and 7 codify support for these populations by mandating that states parties provide “assistance” to individuals impacted by nuclear testing or use and environmental remediation for impacted areas. 

City level resolutions that align with Articles 6 and 7 of the TPNW document local nuclear legacies by explicitly naming how people and/or projects within their jurisdiction have been and continue to be impacted by nuclear weapons development. These impacts include harms to people’s health, environmental destruction, and forced displacement. A significant number of cities reference nuclear legacies within their jurisdictions to contextualize the sense of responsibility around developing nuclear policy.  

For example, the New York City resolution, a result of several years of advocacy by the New York Campaign to Abolish Nuclear Weapons (NYCAN), cites the city as having a “special responsibility, as a site of Manhattan Project activities and a nexus for financing of nuclear weapons,”⁴ to financially divest from companies involved in nuclear armament. This responsibility is further articulated and enshrined by a legislative action to establish an advisory committee on nuclear disarmament.⁵

Likewise, the Back from the Brink resolution passed by the City Council of Chicago, IL, another city in which a historically significant Manhattan Project site––the University of Chicago––is located, expresses responsibilities stemming from the city’s nuclear legacy in a distinctive fashion. The resolution recognizes the disproportionate effects of investing in nuclear weaponry as an inequitable form of security: “WHEREAS, The United States’ continued investment in nuclear weapons fails to address safety and security concerns of communities of color, both at home and abroad, while prioritizing security concerns of white Americans.”⁶ In this resolution, Chicago frames nuclear disarmament as an racial equity issue, bringing an intersectional and transnational approach to the issue of defense and security, a topic that historically has not always been moderated in an inclusive fashion.

Notably, several of the resolutions passed in cities in the Northwest, such as Portland, OR, Milwaukie, OR, Salem, OR, Spokane, WA, and Walla Walla, WA, and the State of Oregon, directly reference communities and lands within their jurisdiction that nuclear weapons development continues to impact. In particular, these resolutions all acknowledge the environmental, “downwind,” and historical legacies of the Hanford Site in Washington, where plutonium was processed from the 1940s to the late 1980s. As Walla Walla’s resolution states, “the Hanford area, which remains one of the most toxic regions in the Western Hemisphere, displaced local residents, affected the health of Downwinders in Washington and Oregon, and caused sacred sites, villages, and fishing areas of Native American tribes to be lost.”⁷ In this text, Walla Walla recognizes the widespread, existing impacts that nuclear weapons development has had on residents of Washington and Oregon. 

The resolutions passed by the Portland City Council and the Oregon State Legislature also draw transnational and intersectional connections between nuclear weapons policies and nuclear frontline communities within their city and state by referencing the U.S. military’s testing of nuclear weapons in the Marshall Islands. As the Portland resolution states, the state of Oregon has “one of the largest populations of Marshall Islanders in the nation, many of whom continue to suffer health consequences from their home being used as a nuclear sacrifice zone.”⁸ By addressing the local needs of the Marshallese community in Oregon, these resolutions draw connections between the concrete harms that the U.S. has produced through nuclear weapons testing in the Marshall Islands and how Marshallese diaspora communities in Oregon  continue to be impacted by this nuclear legacy. In recognizing trans-Pacific legacies of nuclear weapons development, these resolutions powerfully align with Articles 6 and 7 of the TPNW.

Despite their aspirations to influence national policy, city council and state legislature resolutions on nuclear weapons policy are often seen as symbolic. Some cities have attempted to pass legislative actions with “teeth.” Cities such as Madison, WI and New York City have combined these resolutions with divestment policies, but what impact these local actions have had on national nuclear weapons policy is unclear at best. Many Back from the Brink national campaigners and local activists working on city- and state-level actions admit that these resolutions serve primarily as coalition-building and educational tools. 

In our view, however, between the aspirational goals articulated in many of these resolutions and the pragmatic local goals articulated by campaigners and activists, there is an unexplored avenue for global city diplomacy. While federal action is key to advancing multilateral, verifiable nuclear disarmament and addressing nuclear justice issues, including the urgent issue of extending and expanding the Radiation Exposure Compensation Act (RECA), U.S. city leaders, especially those representing individuals and communities affected by nuclear weapons development––such as Marshallese, Native Americans, and Downwinders––have a mandate to elevate the concerns of their constituents about the dangers of nuclear weapons.⁹ As shown in the city council resolutions discussed earlier, city leaders are beginning to acknowledge the local nuclear legacies within their jurisdictions, become more proactive in championing the concerns of local affected communities, and amplifying efforts to prevent the imminent threat of nuclear war. Although the U.S. is not a signatory to the TPNW, the treaty’s inclusive and multi-stakeholder platform affords unique opportunities for U.S. city leaders to represent the voices of the many Americans who are deeply concerned about the dangers of nuclear war and the harm already caused by nuclear weapons in this country. This, in turn, points to a path forward for U.S. cities’ to participate more meaningfully in the global politics of nuclear weapons. The next meeting of States Parties to the Treaty on the Prohibition of Nuclear Weapons in New York City will be on March 3-7, 2025. 

Hirokazu Miyazaki is the Kay Davis Professor and Professor of Anthropology at Northwestern University. Miyazaki has published widely on exchange, hope, and peace based on research in Fiji, Japan, and the U.S. He also serves as a Nagasaki Peace Correspondent. Miyazaki’s current research, supported with a grant from the Carnegie Corporation of New York, focuses on the role of cities in the politics of nuclear weapons. 

Nalani Saito is a Ph.D. student in Sociology at Northwestern University. Her research interests include the intersection of land stewardship and empire with a focus on demilitarization and decolonization in the Pacific. Saito’s current project is on the environmental impacts of militarism in Honolulu.

1. Hirokazu Miyazaki, “Hiroshima and Nagasaki as Models of City Diplomacy,” Sustainability Science, 16: 1215-1228, https://rdcu.be/ck1cu. ↩︎
2.  Back from the Brink is a national campaign to advocate national nuclear security policy changes, such as no first use. They operate local “hubs” across the country to pass local resolutions.  ↩︎
3.  Treaty on the Prohibition of Nuclear Weapons, September 20, 2017, https://treaties.un.org/pages/ViewDetails.aspx?src=TREATY&mtdsg_no=XXVI-9&chapter=26  ↩︎
4.  New York City Council Int. No. 1621. Legis. Sess # 10488. (2019). ↩︎
5.  See Kathleen Sullivan and Matthew Bolton, “Nuclear-free NYC: How New Yorkers are disarming the legacies of the Manhattan Project,” Bulletin of the Atomic Scientists, January 15, 2024.  ↩︎
6.  Chicago City Council R2021-920. (2021). https://chicityclerkelms.chicago.gov/Matter/?matterId=1E85770A-E20D-ED11-82E3-001DD80693B4 ↩︎
7.  Walla Walla City Council. R2021-46. (2021) https://records.ci.walla-walla.wa.us:9443/agenda_publish.cfm?id=&mt=ALL&get_month=3&get_year=2021&dsp=agm&seq=4130&rev=0&ag=1549&ln=25243&nseq=&nrev=&pseq=4136&prev=0# ↩︎
8.  Portland City Council. R37457 (2019). https://efiles.portlandoregon.gov/Record/13358254/File/Document/ ↩︎
9.  The Radiation Exposure Compensation Act (RECA) was originally enacted in 1990 to address compensation claims regarding harms caused by radiation exposure in the context of uranium mining and nuclear testing in the U.S. The law, whose coverage was limited, expired in June 2024. A bill to extend and expand the law was passed by the U.S. Senate in March 2024 and is awaiting House approval.  ↩︎