New START Treaty Expires, Raising Nuclear Risk

For the first time in over half a century, the United States and Russia are no longer bound by a treaty limiting their strategic nuclear weapons. The New START treaty expired on February 5, 2026, removing the last agreed-upon constraints on U.S. And Russian nuclear forces.

What Was New START?

New START, formally known as the Measures for the Further Reduction and Limitation of Strategic Offensive Arms, limited each country to deploying 1,550 strategic nuclear warheads. It likewise restricted the number of deployed intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), and heavy bombers. The treaty included provisions for on-site inspections, data exchanges, and monitoring to verify compliance U.S. Department of State.

The Growing Threat of Nuclear Competition

The expiration of New START coincides with a period of heightened geopolitical tension and a rapidly changing nuclear landscape. China is significantly expanding its nuclear arsenal, and the rivalry between the U.S., China, and Russia is intensifying. This, combined with advancements in weapons technology, raises the potential for a three-way nuclear arms competition.

Such a competition could increase the risk of nuclear conflict, a danger experts believe is higher now than it has been in decades.

Why Nuclear Agreements Matter

Nuclear agreements, even with specific limits on warhead numbers, offer several key benefits:

• Predictability: Reducing the incentive to build up arsenals based on worst-case scenarios.
• Transparency: Providing insight into an adversary’s nuclear forces through data exchanges and inspections.
• Reduced First-Strike Incentives: Limiting weapons that could encourage a preemptive strike.
• Improved Relations: Fostering a more stable relationship through mutual restraint.

A History of Nuclear Restraint

Following the Cuban Missile Crisis in 1962, President John F. Kennedy recognized the dangers of relying solely on nuclear deterrence. He initiated negotiations that led to the Limited Test Ban Treaty in 1963 and established a direct communication line with the Soviet Union. Subsequent U.S. Presidents have also pursued nuclear arms control accords Wikipedia.

Countries committed to non-proliferation under the Nuclear Non-Proliferation Treaty (NPT) expect nuclear-armed nations to demonstrate a commitment to disarmament.

Past Violations and Current Concerns

Critics point to past instances of treaty violations by Russia. However, key elements of previous agreements were implemented, and, as Secretary of State Marco Rubio has noted, these agreements have contributed to the dismantling of over four-fifths of the world’s nuclear weapons.

What’s Next?

While former President Trump considered a proposal from Russia to extend New START limits during negotiations for a new agreement, he ultimately sought a broader deal that would include China’s nuclear forces and Russia’s non-strategic weapons. As of February 5, 2026, no such negotiations are underway Axios.

There is also growing pressure in Washington to increase U.S. Nuclear capabilities to deter both Russia and China. The U.S. Is developing new weapons systems, such as a nuclear-armed sea-launched cruise missile.

The Path Forward

Avoiding an unrestrained nuclear race requires a shared interest in avoiding the economic and security costs associated with such a buildup. While the U.S., Russia, and China all have reasons to avoid escalation, finding a path to new accords will be challenging, particularly with the require to address non-nuclear technologies impacting nuclear balances and the complexities of securing Senate ratification in the U.S.

A potential path forward could involve a “strategic pause,” where the U.S. And Russia agree to refrain from building up their nuclear capabilities while exploring options for future agreements.