April 8 marks the 15th anniversary of the signing of the New Strategic Arms Reductions Treaty (New START).  The treaty verifiably reduced U.S. and Russian strategic nuclear weapons to levels not seen since the 1960s, but its monitoring measures have been suspended.  The treaty in any case expires by its terms in February 2026.

President Donald Trump has expressed interest in “denuclearization.” However, negotiation of a follow-on agreement would have to deal with difficult issues of substance.  We may well face a period of three-way U.S.-Russia-China nuclear arms racing.

New START

Signed in April 2010, New START entered into force in February 2011.  It set three numerical limits for the United States and Russia:  no more than 700 deployed intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs) and heavy bombers equipped for nuclear weapons; no more than 800 deployed and non-deployed launchers for ICBMs and SLBMs and heavy bombers; and no more than 1550 deployed strategic warheads.

The limits meant deep reductions compared to the 1991 START I Treaty. That agreement allowed the United States and Soviet Union each to maintain up to 1600 ICBM/SLBM launchers and heavy bombers and up to 6000 attributed warheads.

New START mandated data exchanges, notifications and on-site inspections to monitor compliance.  Inspections created a significant prospect that cheating would be discovered and thus a strong incentive to stay within the limits.

Treaty Suspended

Presidents Joe Biden and Vladimir Putin agreed to extend the treaty for five years in February 2021.  Unfortunately, in February 2023, Russian officials said Moscow would observe the numerical limits but would suspend the treaty’s monitoring measures.  Washington adopted a similar policy, expressing readiness to resume full compliance if Russia did so.

Using national technical means of verification (for example, surveillance satellites), the United States and Russia likely can confirm the other’s compliance with the 700 and 800 limits.  However, the lack of notifications and on-site inspections make it difficult for the sides to have confidence the other is observing the 1550 limit.

In any event, New START expires in February 2026.  It cannot be extended again.  For the first time in decades, no treaty limits will constrain U.S. and Russian nuclear weapons systems.

What Next?

In January 2025, Trump said he wanted to pursue “denuclearization.” He opined that Russia and China would like to do so as well.  Moscow has suggested readiness to resume strategic stability talks with Washington, which were suspended after Russia’s 2022 invasion of Ukraine.

However, Trump’s first administration engaged Moscow on extending New START only in his last year in office. It tried and failed to include China in the nuclear arms negotiations or secure Russian agreement to limit nonstrategic as well as strategic nuclear weapons.  Trump left office without agreement on New START extension or any other arms agreement.

China’s decision to increase its nuclear arsenal has raised concern in Washington about the challenge of deterring Russia and China at the same time. Some have suggested that New START’s levels may be too confining given the Chinese build-up, though U.S. strategic forces at current levels appear sufficiently robust to deter both countries for some time to come.

What might come after February 2026?  Washington and Moscow could agree to observe New START’s numerical limits for some period, perhaps with a few transparency measures (though not on-site inspections, as Russia allows those only for legally ratified treaties).

A second possibility would use the 2002 Strategic Offensive Reductions Treaty as a model.  That two-page treaty limited the United States and Russia each to 1700-2200 deployed nuclear warheads, but it had no agreed definitions, no counting rules and no monitoring measures.  It was unverifiable.

A third possibility would entail a U.S.-Russia negotiation aimed at a new bilateral treaty.  The Trump administration likely would again seek to put nonstrategic nuclear weapons on the table, which Russia negotiators have resisted in the past.  Moscow has expressed concern about U.S. missile defenses and would like to limit them, but the first Trump administration firmly ruled out constraints on missile defense, and Trump wants a new “Golden Dome” missile defense system to defend America.  The negotiation could quickly bog down over such differences.

If the administration seeks again to bring China into the negotiating process, a fourth possibility, it will have its work cut out persuading Beijing. Russia meanwhile wants to include Britain and France.  A multilateral negotiation among three, four or five nuclear weapons states would prove more difficult than a bilateral negotiation.  Disparate force levels would make it hard to find mutually acceptable limits.

A combination of the third and fourth possibilities could center on a new U.S.-Russia agreement with China, Britain and France undertaking separate measures to constrain their force levels.  That would have to overcome U.S.-Russian differences in a bilateral negotiation and find a way to persuade the other three to accept constraints.

The Most Likely Outcome?

Arms control prospects turn on the participating states’ interest in serious negotiations to reduce and constrain nuclear arms.  At this point, there seems little enthusiasm for such negotiations in Moscow, Beijing or Washington.

That raises the fifth and, unfortunately, most likely possibility:  no follow-on agreement to New START any time soon.  In that case, some in the Pentagon may urge going above the treaty’s limits to respond to China’s build-up.  That would not lead Beijing to scale back its program but almost certainly would prompt Russia to exceed New START numbers as well.  A three-way U.S.-Russia-China arms race would ensue.

After nuclear arms racing in the 1950s and 1960s, the United States and Soviet Union came to realize that, if one side increases its nuclear arsenal and the other does the same, it does not produce a net increase in either’s security. That understanding was key to beginning the first strategic arms talks between Washington and Moscow in 1969.

Hopefully, it will not take too long before Washington, Moscow and Beijing recall that lesson.  In the meantime, we likely will see reduced stability, increased nuclear risk, and greater expenditures of dollars, rubles and yuan.