The Last Treaty Between Russia and the United States on Nuclear Arms Control Expires

The expiration of the New START treaty this Thursday, the last pillar regulating the nuclear arsenals of Russia and the United States, marks a critical turning point as perceived by the international community. Moscow has officially stated that it no longer feels bound by the limits on the deployment of warheads, lamenting Washington's lack of response to a proposal for a twelve-month extension. This pact, signed in 2010 and extended in 2021, imposed verifiable caps on the two powers that hold over 90% of the world's atomic stockpile. As of January 2025, Russia had 4,309 warheads compared to 3,700 for the United States, far ahead of China (600), France (290), or the United Kingdom (225).

The United Nations Secretary-General, António Guterres, described this moment as "serious for international peace and security," highlighting that it is the first time in half a century that the two superpowers are without a binding framework. While the current U.S. administration expresses a willingness to reach a "more effective" agreement potentially including China, the absence of an immediate transition raises fears of a new arms race. Experts note that Beijing has already tripled its arsenal in ten years, prompting Washington to consider ramping up its capabilities to maintain strategic balance.

In light of this growing instability, calls are being made, including from Pope Leon, to replace a "logic of fear" with a shared security ethic. The UN urges Moscow and Washington to resume negotiations without delay to establish a new control regime suited to contemporary technological challenges. Although logistical obstacles hinder immediate expansion of arsenals, the dissolution of decades of nuclear diplomacy comes at a time when the risk of nuclear weapon use is considered the highest since the end of the Cold War.