September 2026
By Amy J. Nelson 

For the first time since the early 1970s, the United States and Russia have no legally binding limits on their strategic nuclear forces. Four months before the New Strategic Arms Reduction Treaty (New START) expired, Russian President Vladimir Putin offered to observe the treaty’s central ceilings informally for one more year while the two sides worked toward a successor.¹ U.S. President Donald Trump declined. Instead, on the day the treaty lapsed—February 5, 2026—he posted on social media that “we should have our Nuclear Experts work on a new, improved, and modernized Treaty that can last long into the future.”² Trump administration officials quickly supplied the missing specifics: not a bilateral extension, but “multilateral nuclear arms control and strategic stability talks” including both Russia and China.³

It is an ambitious answer to a real problem. Judged against 80 years of arms control history, it is also the approach that is most likely to fail, for a reason that runs deeper than great-power rivalry. The conditions that make a comprehensive settlement most necessary are the same ones that make it least attainable. That paradox has governed this field since 1945, and it points to a way through.

Not a Pause

New START’s verification architecture—data exchanges, on-site inspections, and telemetry sharing—was built for a bipolar world: two comparably sized arsenals, one shared interest in predictability. That world is gone, and it went in three directions at once. Russia curtailed inspections and data declarations in 2023, well before the treaty formally lapsed. China’s arsenal has grown entirely outside any transparency regime, from roughly 260 warheads a decade ago to an estimated 620 today,⁴ with the Pentagon projecting more than 1,000 by 2030.⁵ And commercial satellite imagery and open-source analysis now do quietly what treaty inspectors used to do openly.⁶

Of the three changes, open-source visibility is the least appreciated and most consequential. Arms control’s core trade was visibility for restraint: Each side accepted intrusive disclosure because the disclosure went to a single, symmetrical adversary bound by the same limits. In a world with three main competing powers, that logic inverts. What Washington reveals to reassure Moscow is also read in Beijing, by a state bound by nothing. Verification has become a channel through which information reaches a party that never signed, and the governing question is no longer how much to disclose but to whom, about what, and in what sequence.

The institutional evidence arrived on schedule, and at the venue where the Trump administration was making its own case. Opening the nuclear Nonproliferation Treaty (NPT) 2026 Review Conference in New York in late April, U.S. Assistant Secretary of State Christopher Yeaw argued that all five nuclear-weapon states recognized under the NPT bear Article VI responsibilities, and that this was precisely why Washington has proposed multilateral strategic stability and arms control talks.⁷ China’s director-general for disarmament, Sun Xiaobo, answered that the proposal was “in essence an attempt [by the United States] to shift its special and primary responsibilities as a country with the largest nuclear arsenal onto others.” China, he said, “has no interest in them.”⁸ In May, the United States, the United Kingdom, and France issued a joint statement urging all five NPT nuclear-weapon states to engage. Russia and China were not party to that statement.⁹

What the five managed to do together is more revealing. Divided on nearly everything else, they worked in concert to strip the draft review conference outcome document of the specific commitments that would have obliged them to reduce the number and salience of their weapons.¹⁰ The conference closed May 22 without consensus—the third consecutive failure, and 16 years since states-parties last agreed on a final document.^{11 12} This outcome proved that these five states can coordinate, but what they coordinate on is the avoidance of specific obligations. None of this reflects a pause. A pause implies something that can be resumed, and the conditions under which New START was written are not returning.

Is There Anything New Here?

The instinct to go multilateral is not new, as the record shows. British Defense Secretary Des Browne proposed five-party talks at the Conference on Disarmament in Geneva in 2008, and the P5 process, a consultative mechanism initiated in 2009 to facilitate cooperation among the NPT’s five nuclear-weapon states, has met, on and off, ever since.¹³ Eighteen years in, the process has produced joint statements on strategic stability and support for the Comprehensive Test Ban Treaty.¹⁴ It has not produced a single limit on anyone’s nuclear forces. What happened in New York this year was not an aberration. It was the process working as it always has.

Alexey Arbatov, a Russian nuclear expert, laid out the structural reason for that record in June 2026: The United States, the UK, and France are allies with no interest in constraining one another, while Russia and China have voiced no mutual concern about each other’s arsenals since the late 1980s.¹⁵ Mutual deterrence and rough parity are what made the Strategic Arms Limitation Talks (SALT I) and the Intermediate-Range Nuclear Forces (INF) Treaty, both between the United States and the Soviet Union, tractable. Without them, a shared ceiling has nothing to anchor it.

The Trump administration’s declared ambition—a new treaty that would mean “taking into account for all Russian nuclear weapons, both novel and existing strategic systems, and addressing the breakout growth of Chinese nuclear weapons stockpiles”¹⁶—asks five states with five different threat perceptions to accept a single common framework. The one state whose growth supplies the rationale (China) has already declined and pointed the United States back toward Russia.

Arbatov is right, and his argument can be carried further. Parity of weapons stockpiles explains who can get to the table. It does not explain what happens once they sit down. Across negotiations—from the 1946 Baruch Plan through the 2019 Hanoi summit to the collapse of the 2015 Iran nuclear deal, formally known as the Joint Comprehensive Plan of Action (JCPOA), and the maximalist demands that followed—the variable that mattered most was not whether talks were bilateral or multilateral, nor even whether the parties held comparable arsenals; it was how each side chose to handle irreducible uncertainty about the other’s intentions and capabilities.¹⁷ States that tried to eliminate that uncertainty in one comprehensive settlement, requiring the other side to resolve every open question before any cooperation could begin, reliably failed. States that managed uncertainty incrementally, trading narrow and verifiable steps that left each side’s core deterrent intact, reliably succeeded. SALT I capped select delivery systems, not entire arsenals. The INF Treaty eliminated one symmetrically threatening class of missiles, not nuclear weapons generally. Even the JCPOA, an unusually ambitious deal, constrained Iran’s program rather than eliminating it outright, and it held as long as it did precisely because it left the harder questions of Iranian intentions unresolved rather than pretending to answer them.

The intuition to seek narrower solutions is correct. Any durable future framework must now account for more sources of uncertainty than New START ever did: Russian modernization and novel systems on one side, Chinese nuclear stockpile growth on the other. Although the diagnosis is right, the implementation repeats the nuclear arms control field’s oldest error: bundling every source of uncertainty into a single comprehensive settlement, restated for a five-party table instead of a two-party one.

A genuinely new idea follows from my forthcoming book’s central argument: that arms control has succeeded when it managed irreducible uncertainty and failed when it tried to eliminate it.¹⁸ That logic persists. In the current new treaty-thin environment, where no verification regime remains to convert disclosure into assurance, managing uncertainty means governing it directly. This is what I have called “disciplined ambiguity”—the deliberate, bounded management of uncertainty to signal intent without exposing operational detail.¹⁹ Its premise is that not all uncertainty is alike. Uncertainty about political commitments and escalation thresholds breeds alarm and forces inference under pressure. Uncertainty about operational specifics—patrol patterns, deployment configurations, and response options—complicates an adversary without obscuring intent. The discipline lies in telling the two apart: clarifying commitments while preserving indeterminacy precisely where precision would create vulnerability.

In practice, this means controlled disclosure of new systems without deployment timelines or operating parameters, reciprocal notification of major exercises and tests, and communicated red lines, identifying which actions would be treated as destabilizing. This may seem like a downshift from arms control. It is, instead, what is achievable today. It does not require five capitals to agree on a shared ceiling. Instead, disciplined ambiguity requires that each dyad of nuclear powers decides separately and sequentially what to reveal, what to withhold, and how to signal intent. It is not a substitute for agreement but a practice for the interval before one—arguably a harder discipline to sustain than signing a treaty, but one that states can begin practicing now without waiting for China to change its mind about parity.

Who Leads, and Toward What?

Who, if anyone, is positioned to lead arms control’s next era, and toward what end? The Trump administration’s messaging to date provides no answers to these questions. In July 2025, Trump himself reportedly expressed interest in maintaining only New START’s central limits; by February 2026, he had rejected that course in favor of a treaty that no one in his government could yet describe.²⁰ One senior U.S. State Department official has said that a new treaty must capture the full scope of Russian and Chinese arsenals.²¹ Another official, asked directly whether an informal understanding with Russia to hold force levels steady already existed, said only, “I know of no such agreement.”²² Trump told an interviewer in January that he would “do a deal with Russia without the Chinese,”²³ if he had to—a bilateral instinct dressed in multilateral language. When Trump and Chinese President Xi Jinping met in Beijing in May, a White House fact sheet released afterward claimed a shared commitment to denuclearizing North Korea; it said nothing about China’s own arsenal because Chinese negotiators declined to discuss it.²⁴ Washington has announced a negotiation it cannot yet describe with a partner that has not agreed to come.

That vacuum is precisely where the hardest question lives: Does the world end up with most nuclear weapons managed by a handful of strongmen rather than by institutions? In one narrow sense, this has always been the case: The authority to launch nuclear weapons everywhere rests with a small number of executives, elected or not. What is new is the source of the constraint on those executives. For five decades, it was institutional: negotiated by professionals, ratified by legislatures, verified by inspectorates. The risk now is that constraint becomes personal, negotiated leader to leader, deal to deal, with no institutional commitment or memory that survives a change of government.

A version of this scenario is already playing out. The June 2026 memorandum intended to end hostilities between the United States and Iran was negotiated bilaterally,²⁵ outside the P5+1 structure (China, France, Germany, Russia, the UK, and the United States) that produced the JCPOA, and its nuclear provisions run to a single vague paragraph with no verified baseline and no snapback mechanism comparable to the one built into the 2015 Iran nuclear deal. It postponed the nuclear question rather than answered it.²⁶ If the multilateral nuclear talks that Trump has proposed follow the same model—summit-driven, thinly staffed, dependent on the goodwill of whoever occupies the Kremlin, Zhongnanhai, and the White House—then, at a given moment, frameworks will indeed have given way to personalities. Institutions that once absorbed and outlasted individual leaders are being replaced by arrangements that will not survive a single election.

What Should Happen Instead

None of this means multilateral engagement is worthless, only that it is being asked to do the wrong job. The P5 process has an 18-year record of producing shared vocabulary and doctrinal exchange, but no numerical limits; it should be tasked with exactly that kind of norm-building, including work on crisis communication and testing moratoria, rather than the kind of treaty text that it has never been able to deliver. Alongside that process, Washington should pursue narrow, sequenced, bilateral tracks. With Moscow, the priority should be an informal understanding to hold deployed strategic force levels steady while negotiators work toward a successor arrangement, paired with reciprocal transparency on nonstrategic nuclear weapons, long-range conventional strike systems, and novel strategic capabilities such as nuclear-powered cruise missiles and undersea autonomous systems.

With Beijing, the emphasis should remain on risk reduction rather than parity. This approach would include advance notification of ballistic missile launches and major strategic exercises; protocols governing dual-capable missile operations; exchanges on launch-on-warning and command-and-control practices; crisis communication procedures; and transparency measures regarding the expansion of China’s missile silo fields. Both tracks should apply the incremental logic to which my research points: narrow, verifiable, sequenced steps focused on the capabilities most likely to lead to miscalculation, rather than comprehensive settlements that ask each side to resolve every outstanding issue before either side gains anything.

Trump is right that the New START era cannot simply be extended by another five years; the treaty itself forecloses that option, and the strategic environment for which it was designed no longer exists. He is also right that China’s arsenal cannot be indefinitely excluded from any conversation about strategic stability, but recognizing the problem is not equivalent to identifying the solution. The solution on offer, a single comprehensive multilateral treaty, repeats the very error that has frustrated most major arms control initiatives since 1945. A framework rebuilt instead on incremental, disciplined management of uncertainty, pursued through parallel bilateral channels rather than all-or-nothing negotiation, has a far stronger historical record.

Whether this administration or the next chooses the harder and less photogenic path will determine whether the coming years mark the start of a new arms control era or simply the interval between frameworks, filled, as such intervals always are, with force and the private judgment of whoever holds the launch codes.

ENDNOTES

1. Vladimir Putin, “Meeting with permanent members of the Security Council,” press release, September 22, 2025.

2. Donald Trump, “The United States is the most powerful Country in the World. I completely rebuilt its Military in my First Term,” Truth Social, February 5, 2026.

3. Congressional Research Service, “U.S.-Russian Nuclear Arms Control: Overview and Potential Considerations for Congress,” February 26, 2026.

4. Hans M. Kristensen, Matt Korda, Eliana Johns, and Mackenzie Knight-Boyle, “Chinese nuclear weapons, 2026,” Bulletin of the Atomic Scientists, Vol. 82, No. 4 (2026), pp. 293-322.

5. U.S. Department of Defense, “Annual Report to Congress: Military and Security Developments Involving the People’s Republic of China,” December 23, 2025.

6. Hans M. Kristensen, and Matt Korda, “China Is Building A Second Nuclear Missile Silo Field,” Federation of American Scientists, July 26, 2021.

7. Christopher Yeaw, “Statement by the United States to the NPT Review Conference,” U.S. Mission to International Organizations in Geneva, April 29, 2026.

8. Sun Xiaobo, “Statement by Sun Xiaobo, Director-General of the Department of Arms Control of the Foreign Ministry of China at the General Debate of the Eleventh Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT),”Ministry of Foreign Affairs of the People’s Republic of China, April 29, 2026.

9. “P3 Joint Statement for Main Committee I 2026 Review Conference of Treaty on the Non-Proliferation of Nuclear Weapons,” Permanent representation of France to the Conference on Disarmament, May 1, 2026.

10. Libby Flatoff, and Daryl G. Kimball, “2026 NPT Review Conference Stymied by Disputes,” Arms Control Today, Vol. 56 (June 2026).

11. United Nations, “Review Conference Ends without Consensus Outcome amid Rising Nuclear Risks,” meetings coverage, May 22, 2026.

12. United Nations, “(Informal Consultations) 2026 Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons,” March 3, 2026.

13. Maximilian Hoell, and Andreas Persbo, “Overcoming disunity: Reinvigorating the P5 Process a decade on,” report, European Leadership Network, July 30, 2020.

14. Arms Control Association, “P5 Reiterate Commitment to CTBT,” July 1, 2011.

15. Alexey Arbatov, “The Puzzle of Multilateral Arms Control,” Arms Control Today, Vol. 56 (June 2026).

16. Thomas G. DiNanno, “Statement to the Conference on Disarmament,” U.S. Department of State, February 6, 2026.

17. Amy J. Nelson, The Arms Control Paradox (Stanford University Press, 2026).

18. Ibid.

19. Amy J. Nelson, “After New START: The Case for Disciplined Ambiguity,” New America, February 23, 2026.

20. Trump, “The United States is the most powerful Country in the World.”

21. Olivia Le Poidevin, “US meeting Russian and Chinese delegations for nuclear arms control talks, official says,” Reuters, February 24, 2026.

22. Alex Raufoglu, “New START: No ‘Gentleman’s Agreement’ Between US, Russia On Expired Nuclear Treaty,” Radio Free Europe/Radio Liberty, February 17, 2026.

23. Donald Trump, “Two Hours, Scores of Questions, 23,000 Words: Our Interview With President Trump,” interview by Zolan Kanno-Youngs, Tyler Pager, Katie Rogers, and David E. Sanger, The New York Times, January 11, 2026.

24. The White House, “Fact Sheet: President Donald J. Trump Secures Historic Deals with China, Delivering for American Workers, Farmers, and Industry,” May 17, 2026.

25. Abigail Williams, “Text of the Iran-U.S. memorandum of understanding,” NBC News, June 17, 2026.

26.  Amy J. Nelson, “What the Iran MOU Gets Right, Gets Wrong, and Leaves Unresolved,” New America, June 25, 2026.