On October 24, 2020, Honduras became the fiftieth country to ratify the United Nations treaty to ban nuclear weapons, starting a ninety-day countdown to the date it would enter into force. As of Friday, January 22, the Treaty on the Prohibition of Nuclear Weapons (TPNW), also known as the “nuclear ban treaty,” is now active. With fifty-one states having ratified the treaty, and another eighty-seven publicly supporting it, the TPNW serves to signal a broad international desire to further stigmatize nuclear use and encourage disarmament and nonproliferation.

The TPNW, which prohibits state parties from developing, producing, possessing, or doing just about anything else with nuclear weapons short of destroying them, has been a controversial document since its inception just over three years ago. A glance at the list of signatories and supporters reveals why. While the nuclear ban treaty has near-ubiquitous support in Africa and Latin America, and majority backing in the Middle East and Asia, the United States and its NATO and Asian allies have joined the nuclear-armed countries of Russia, China, India, Pakistan, North Korea, and Israel to oppose it. Indeed, in 2018, the five permanent (P5) members of the UN Security Council publicly explained that the TPNW “contradicts, and risks undermining” the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), the foundational nonproliferation treaty that entered into force in March 1970. In calling for a renewed commitment to the NPT, the P5 asserted that,

The TPNW fails to address the key issues that must be overcome to achieve lasting global nuclear disarmament…ignores the international security context and regional challenges, and does nothing to increase trust and transparency between States. It will not result in the elimination of a single weapon. It fails to meet the highest standards of non-proliferation. It is creating divisions across the international non-proliferation and disarmament machinery, which could make further progress on disarmament even more difficult.

According to the P5, the NPT’s success is that it has already “produced tangible results, including deep reductions in the global stockpiles of nuclear weapons.” This is factually true; Cold War nuclear weapons stockpiles have declined by over 55,000 warheads, mostly owed to cuts from Russian and American arsenals, to approximately 13,500 today. Still, the NPT has been imperfect at best; President John F. Kennedy’s 1963 warning that the world would see an additional fifteen or twenty nuclear-armed states by 1975 may not have come to pass, but several states—India, Pakistan, Israel, and North Korea—successfully proliferated after the NPT came into force while others, like Iraq and Syria, secretly violated it for years without detection.

Moreover, the 13,500 existing weapons today, in addition to multiple nuclear weapons states’ plans to modernize their arsenals, represent a salient violation of the bargain that is central to the NPT’s longevity: states with nuclear weapons commit to disarm in exchange for a pledge by everyone else to not proliferate. The Trump administration’s recent moves to dismantle existing arms control agreements, including the Joint Comprehensive Plan of Action (JCPOA) with Iran, Intermediate-Range Nuclear Forces Treaty (INF) with Russia, and Open Skies Treaty, are just the latest indications that the world’s preeminent nuclear power may not be interested in fulfilling its commitment anytime soon. President Joe Biden’s decisions to reinstate some of these agreements, such as reentering the JCPOA and saving the New START Treaty from expiration, will not assuage the many non-nuclear weapons states that are fed up with slow American and international progress on disarmament and even backpedaling in response to technological innovations with new military applications.

This international fervor has put many U.S. allies, especially those without nuclear weapons of their own, in a tough position. In fact, considering that only the United States offers nuclear security guarantees to other states and that the TPNW expressly prohibits state parties from transferring, receiving, and stationing nuclear weapons on their territory, it could be said that the treaty creates a unique problem for America and its allies. As University of Southern Maine Professor Rebecca Davis Gibbons has observed, a global norm that stigmatizes nuclear weapons would be “dangerous” for the United States. By “bringing attention to the devastation wrought by nuclear weapons,” Gibbons says, U.S. allies “will face pressure to join the treaty, undermining extended nuclear deterrence.”

Heather Williams, a Stanton Nuclear Security Fellow at MIT, has noted that this is already occurring; Both the German and Belgian governments have faced resistance to U.S. nuclear weapons deployments on their territories, and fifty-six former NATO leaders have endorsed the nuclear ban treaty as a means to “help end decades of paralysis in disarmament.” Even the Japanese government, which opposes the nuclear ban treaty despite being the only country to be targeted with nuclear weapons, is under pressure to ratify the treaty from a majority of the Japanese public.

For now, these efforts appear nascent and unlikely to shift European or Asian security perceptions to permit ascension to the TPNW. However, pressure works through persistence, and change can happen quickly. “To the nations who believe they are sheltered under the umbrella of nuclear weapons, will you be complicit in your own destruction and the destruction of others in your name?” asked Beatrice Fihn, the director of the International Campaign to Abolish Nuclear Weapons, the organization that spearheaded the advocacy which brought the nuclear ban treaty to fruition in 2017. As advocates question states’ culpability regarding the potential use of nuclear weapons, and the prospect of nuclear catastrophe continues to grow, how will U.S. allies respond?

Adam Lammon is assistant managing editor at The National Interest. Follow him on Twitter @AdamLammon.

Image: Wikipedia.