The last remaining nuclear arms treaty between the United States and Russia expired today, , marking a significant turning point in arms control history since the Cold War. The treaty’s lapse has ignited fears of a renewed nuclear arms race, a concern echoed by international leaders and arms control advocates.
United Nations Secretary-General António Guterres described the expiration of the New START treaty as a “grave moment for international peace and security,” urging the U.S. And Russia to quickly reach a new framework. He warned that the dissolution of decades of arms control achievements comes at a particularly dangerous time, stating the risk of nuclear weapon use is at its highest level in decades.
Signed in 2010, New START limited each party to 800 deployed launchers and heavy bombers, and 1,550 strategic offensive nuclear warheads, with a verification mechanism to ensure compliance. Its expiration ushers in an era of less constrained nuclear development, particularly as on-site inspections were suspended in 2023 following Russia’s large-scale offensive in Ukraine, launched in February 2022.
Washington Temporizes
In September 2025, Russian President Vladimir Putin proposed extending the treaty’s terms for one year, a suggestion initially described as a “good idea” by U.S. President Donald Trump. However, the United States did not follow through with the extension.
Russia declared itself “no longer bound” by the treaty as of Wednesday, . A statement from the Russian Foreign Ministry indicated that “We proceed from the fact that the parties to the New START treaty are no longer bound by any obligations or mutual declarations within the framework of the treaty.”
Despite this declaration, Moscow signaled a cautious approach. President Putin, during a conversation with Chinese President Xi Jinping on Wednesday, “stressed that in this situation, we will act thoughtfully and responsibly,” according to Yuri Ushakov, the Russian president’s diplomatic advisor. Ushakov added that Russia “remains open to seeking ways to negotiate and ensure strategic stability.”
U.S. Officials have offered a more measured response. Secretary of State Marco Rubio stated Wednesday that President Trump would address the issue “later,” without specifying a timeframe, and reiterated the U.S. Position that any discussions must include China.
Europe Points to Moscow
European capitals have issued calls for a resolution, while largely placing responsibility for the treaty’s failure on Moscow. France, the sole nuclear power within the European Union, has urged major nuclear powers – the U.S., Russia, and China – to work towards an international arms control system.
With the end of New START, “This represents the disappearance tomorrow of all limits on the world’s largest nuclear arsenals for the first time since the Cold War. This is the culmination of a series of setbacks in international standards contributing to strategic stability,” according to the French Foreign Ministry, which identifies “Russia” as “responsible for these setbacks.”
The International Campaign to Abolish Nuclear Weapons (ICAN) has also apportioned blame, calling on both Russian and American leaders to publicly commit to respecting the limits of the New START treaty “during the negotiation of a new framework.”
The expiration of New START removes the last bilateral verification mechanism between the two nations possessing the largest nuclear stockpiles. Without the treaty’s constraints and inspection protocols, the potential for miscalculation and escalation increases, raising concerns about a return to the unchecked arms buildup that characterized much of the Cold War. The treaty’s demise also casts a shadow over broader international efforts to prevent nuclear proliferation and safeguard global security.
The Bulletin of the Atomic Scientists recently moved the Doomsday Clock to 85 seconds to midnight – the closest it has ever been – citing the expiration of New START as a contributing factor to the increased global risk. The future of nuclear arms control remains uncertain, with the path forward dependent on the willingness of the U.S., Russia, and other key players to engage in meaningful dialogue and forge new agreements.
