New START Treaty Expiry: Why the World Faces a New Nuclear Arms Race

The New Strategic Arms Reduction Treaty (New START), the final bilateral pact limiting the U.S. and Russian nuclear arsenals, formally expired on February 5.

Origins and Background of the New START Treaty

In the late 2000s, Washington and Moscow underwent a diplomatic reset that resulted in the New START pact. Signed in 1991, START I was its predecessor and ended in December 2009. The START era’s stringent verification and monitoring procedures were absent from the 2002 Moscow Treaty, even though it was still in force.

Following a meeting between then-US President Barack Obama and his Russian counterpart Dmitry Medvedev in London in April 2009, serious negotiations for a replacement got underway.

Negotiations and Ratification Process

There were multiple rounds of negotiations in Moscow and Geneva during the drafting phase. The two leaders signed the agreement in Prague in April 2010, and it became operative on February 5, 2011, following a difficult ratification procedure in the US Senate and approval by the Russian Federal Assembly.

Verifiable limits on both countries’ strategic offensive weapons were established by New START, which required both sides to meet and maintain these limits within seven years (by February 5, 2018).

Core Provisions and Verification Measures

It forbade each party from interfering with the other’s National Technical Means (such as satellites), allowed 18 on-site inspections annually, set a bilateral commission to settle disputes, and capped the number of deployed strategic warheads at 1,550.

It also placed similar restrictions on the number of heavy bombers, ICBMs, and SLBMs.

Strategic Disputes and Emerging Technologies

Nevertheless, New START encountered a number of obstacles during its existence that ultimately led to its downfall.

First and foremost, Russia frequently claimed that American missile defense systems upset the strategic balance by implying that the “mutually assured destruction” dynamic would be disrupted if one side could neutralize the other’s retaliatory strike.

On the other hand, the United States voiced worries about conventional quick global strike capabilities, which involve the placement of precision conventional warheads on ballistic missiles—systems that New START considered to be within its nuclear constraints.

New Strategic Weapons Outside Treaty Limits

Russia also announced a number of new strategic systems in the latter half of the treaty’s existence, such as the Avangard hypersonic glide vehicle and the Sarmat heavy ICBM.

Other systems, including as the nuclear-powered underwater drone Poseidon and the nuclear-powered cruise missile Burevestnik, remained outside the treaty’s technical parameters, causing conflict, despite the United States’ successful effort to get these counted under New START.

Extension, Suspension, and Collapse

Originally, 2021 was the treaty’s expiration year.

The Biden administration and the Kremlin reached a one-time, five-year extension just days before the deadline, rescheduling the expiration date to February 5, 2026.

However, President Vladimir Putin announced in February 2023 that he was suspending Russia’s participation in New START after the conflict in Ukraine intensified and damaged bilateral relations.

Moscow claimed that the U.S. was attempting to “strategically defeat” Russia and that on-site inspections in Russia were impossible due to Western aid to Ukraine.

Soon after, the United States withheld its own alerts and data.

Strategic Uncertainty and Deterrence Risks

Throughout 2024 and 2025, talks for a successor treaty—often referred to as Post-New START—have stalled.

In late 2025, the Trump administration expressed a preference for a “better arrangement” in response to a Russian proposal for a voluntary one-year informal adherence to the 1,550 quota.

As a result, the two biggest nuclear arsenals in the world are no longer subject to legal restrictions.

There are no legally binding restrictions on the quantity of strategic nuclear weapons that the United States and Russia may use for the first time since 1972.

With the elimination of official routes for confirming the positions and status of nuclear forces, intelligence services are now solely dependent on satellite imaging and other unilateral techniques.

Additionally, both countries have the technical capacity to transfer thousands of stored warheads to current missiles in the absence of the 1,550 cap—a maneuver that was previously forbidden under the pact.

Global Nonproliferation Challenges

The context in which each government evaluates the other’s credibility may therefore shift, even while the traditional logic of deterrence—that each side abstains because it anticipates a disastrous reaction—remains valid.

Both parties will revert to independently gathering and analyzing data in the absence of the New START infrastructure, which is more prone to mistakes and more easily politicized.

The entanglement of nuclear and non-nuclear strategic systems and the value both sides place on non-contact options like precision conventional strikes and cyberattacks, which can jeopardize nuclear command and control without crossing a nuclear threshold, are other contemporary deterrence issues.

China and Multilateral Arms Control Deadlock

For this reason, rather than focusing only on the emergence of new warheads, analysts like Karim Haggag of the Stockholm International Peace Research Institute have emphasized the loss of predictability.

Second, it will be more difficult to include China and other nuclear-armed states in a broader nonproliferation framework in practice once New START expires.

It is also more difficult because China has publicly maintained that it is “neither fair or logical” to demand that it be included in their disarmament framework at this time.

Beijing might legitimately contend that before asking others to assume comparable responsibilities, the two biggest arsenals must first restore verifiable boundaries.

Incremental Paths Forward

Thomas Countryman, the chairman of the board of the Arms Control Association, stated in 2025 that the most practical short-term course is a regime with three pillars.

In fact, despite its inconsistent output and pace in recent years, the current P5 process is frequently mentioned as one of a few standing platforms for this type of incrementalism.

Frequently Asked Questions

1. What was the significance of the New START treaty?

In terms of nuclear armaments control, New START was the final legally binding agreement between the US and Russia.

2. What eventually caused New START to expire?

Disagreements over missile defense and new military systems, slow negotiations for a replacement accord, and worsening US-Russian relations.

3. Does the expiration of New START imply an imminent increase in nuclear weapons?

Not right away.

4. What impact does the treaty’s failure have on international nuclear nonproliferation?

It makes the global nonproliferation regime seem less credible.

5. Are there currently workable alternatives to a comprehensive weapons control agreement?

Restoring fundamental transparency and confidence-building measures.

Conclusion

An important and unsettling turning point in the history of nuclear control worldwide is the expiration of New START.

The post-New START era runs the potential of being characterized by distrust, fragmentation, and unbridled nuclear rivalry rather than stability through deterrence.

Disclaimer: This article is for informational and analytical purposes only. It does not express any official policy position or predict future actions by governments or institutions.