The New Strategic Arms Reduction Treaty (New START) between the United States and Russia expired on February 5, 2026, at midnight, ending the last remaining bilateral nuclear arms control agreement between the two countries. New START imposed limits on the number of deployed strategic nuclear warheads and delivery systems, capping each side at 1,550 warheads and 700 deployed launchers, including intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), and heavy bombers. The treaty also established a verification regime involving on-site inspections, data exchanges, and notifications to ensure compliance.
Originally signed in 2010, New START replaced the Strategic Offensive Reductions Treaty (SORT) and was the first verifiable nuclear arms control treaty in over a decade. It entered into force in 2011 and was intended to last for ten years, with provision for a possible five-year extension, which the United States and Russia agreed on in early 2021. The measure aimed to enhance strategic stability by limiting the numbers and types of nuclear forces while providing transparency between the two largest nuclear weapon states.
The expiration marked a significant moment for international security, eliminating the last formal constraints on the size of the strategic nuclear arsenals of Washington and Moscow. The United Nations Secretary-General identified the expiration as a grave development for global peace and security, highlighting the increased risks posed by the absence of mutual verification and transparency measures.
Since the treaty regulated only strategic nuclear weapons, it did not cover tactical or non-strategic nuclear arms, leaving a gap in the overall arms control architecture. The termination of New START also reflects broader challenges in U.S.-Russia relations and arms control diplomacy, with no immediate plans for renewal or replacement announced by either government.
New START had played a key role in monitoring and reducing nuclear risks during a period marked by ongoing geopolitical tensions, including conflicts and sanctions between the two nations. The treaty’s verification mechanisms had provided valuable insight into nuclear force developments, contributing to strategic stability despite deteriorating political relations.
Prior to New START, the START I treaty, signed in 1991, established initial reductions and verification standards, but its provisions have long since expired. The loss of New START revokes established limits and transparency obligations, reducing oversight over the world’s largest nuclear arsenals for the first time in more than three decades.
The treaty’s expiration also coincides with broader discussions among arms control advocates and international organizations about pathways to reinstate nuclear arms control agreements or develop new frameworks addressing modern weapons technologies and emerging security threats. However, the termination of New START ended a comprehensive system of mutual constraints and verifications that had governed U.S.-Russian strategic nuclear forces since its implementation.
