After New START Lapse, White House Weighs More Nuclear Arms and Tests

In the days after the New START treaty expired on Feb. 5, 2026, the Biden-to-Trump presidential administration signalled a shift in U.S. nuclear posture: officials say Washington is considering redeploying warheads from storage and has instructed aides to prepare to resume nuclear explosive testing. The moves would reverse nearly four decades of stricter U.S. limits on deployment and testing, and would mark the first time since 1992 that a U.S. president has ordered a return to explosive tests if carried out. Administration statements so far are deliberately vague about scale and timelines, leaving analysts to weigh whether the steps are intended to prompt new trilateral negotiations with Russia and China or to begin a new arms competition. The coming weeks will be decisive for capabilities planning and for diplomatic responses from Moscow and Beijing.

Key Takeaways

• The New START treaty between the United States and Russia expired on Feb. 5, 2026, ending limits that capped deployed strategic warheads at roughly 1,550 per side.
• White House officials have publicly discussed using warheads held in storage to increase deployed forces, though no numbers or force mixes have been specified.
• The administration has directed aides to prepare for a nuclear explosive test; the last U.S. test was conducted in 1992.
• Thomas G. DiNanno, the State Department under secretary for arms control, told the Conference on Disarmament that New START placed “unilateral constraints” on the United States.
• Nuclear managers and former officials say technical and logistical preparations for a detonative test would take time, even if policy authorization is issued quickly.
• Experts warn that unclear intent and lack of transparency could increase misperception risks among nuclear-armed states and allies.
• If implemented at scale, redeployments and testing would alter U.S. force posture and could prompt reciprocal measures from Russia and China.

Background

New START, negotiated in 2010, set numerical caps on deployed strategic nuclear delivery systems and warheads and provided a verification framework that helped stabilize U.S.-Russia strategic relations for 15 years. The treaty capped deployed strategic warheads at approximately 1,550 for each side, limited deployed delivery systems to 700, and set an overall launcher cap of 800. Over the past three decades U.S. policy emphasized maintaining a safe, secure and effective deterrent while reducing the number of weapons that are actively deployed.

Since 2019, U.S.-Russia arms control relations have frayed: the United States withdrew from the Intermediate-Range Nuclear Forces Treaty and the Open Skies Treaty during the previous administration, citing Russian violations. Those moves, plus modernization programs in Moscow, Beijing, and Washington, eroded the institutional ties that sustained bilateral arms control dialogue. New START’s verification regime had been the last major constraint with legally binding inspections and data exchanges.

Domestic stakeholders include the Department of Defense, the National Nuclear Security Administration (NNSA), Congress, and nuclear-armed allies in NATO and the Indo-Pacific. Their priorities range from sustaining deterrent credibility and stockpile safety to limiting escalation risks and preserving nonproliferation norms. Any decision to alter deployments or to resume explosive testing would require interagency coordination and would quickly become a central subject of allied consultations and congressional oversight.

Main Event

Within five days after New START expired, senior administration officials publicly floated options to reuse warheads currently held in storage and to conduct an explosive nuclear test. Officials described a menu of possibilities rather than a single, final decision: some options focus on increasing the number of warheads mated to deployed delivery systems, while others contemplate different kinds of diagnostic or experimental detonations. No official has provided figures for how many warheads might be moved or what performance objectives a test would target.

On the same day the treaty lapsed, Thomas G. DiNanno addressed the Conference on Disarmament in Geneva and argued that New START had imposed constraints the administration deemed unacceptable. His speech reiterated prior complaints about Russian treaty violations that helped justify earlier U.S. treaty withdrawals. DiNanno’s appearance signalled that the State Department would advocate for a changed negotiating posture rather than an informal extension.

Administration aides say President Trump authorized staff to prepare the policy, legal and technical work needed to resume an explosive test if the president orders it; they stress that preparation is distinct from an order to detonate. The National Nuclear Security Administration and Department of Energy would play lead roles on any testing program, and service components would be involved in deployment logistics. Officials note that restoring a testing program after decades of moratorium would require rebuilding or validating facilities, instrumentation, and safety practices.

Analysis & Implications

Resuming explosive tests or substantially increasing deployed warheads would have several consequences. Technically, explosive testing provides calibration data that can inform warhead design and certification; politically, it sends a highly visible signal of intent and capability. For allies that rely on U.S. extended deterrence, such moves could be reassuring in the short term but destabilizing if they trigger reciprocal build-ups by Russia and China.

Diplomatically, the White House may be using the possibility of force-posture changes as leverage to push Moscow and Beijing into a new round of talks that cover all three major nuclear powers. However, without credible verification measures and clear ceilings, any new agreement would likely fall short of restoring the predictability New START provided. A three-way negotiation would be unprecedented and technically complex given differences in force structure and transparency among the three states.

Economically, a large-scale redeployment and modernization push would raise procurement and lifecycle costs for warheads, delivery systems, and command-and-control upgrades. Congress would need to authorize funding increases; that could provoke contentious hearings and budget trade-offs with conventional defense priorities. The industrial base that sustains warhead maintenance and potential testing is limited and would face near-term capacity constraints.

Strategic risk is a central concern. Ambiguity about timing, scale and purpose increases the chance of miscalculation, especially during crises. Restoring explosive testing could also erode the global norm against nuclear detonations and complicate nonproliferation diplomacy with states that have abstained from testing for decades.

Comparison & Data

The table places the current policy moment in historical context. New START provided numerical limits plus inspection mechanisms; without it, strategic transparency drops. The technical gap between laboratory-based stockpile stewardship and full explosive testing is significant: stewardship sustains confidence but cannot produce the same live-yield data as detonations.

Reactions & Quotes

Officials, experts and public reactions have been mixed, with allies urging consultation and some former officials expressing surprise at the administration’s openness to testing.

“It’s all a bit mysterious,” said Jill Hruby, who ran the NNSA until last year, summarizing the uncertainty many technical experts feel about the administration’s near-term intentions.

Jill Hruby, former NNSA director

State Department representation to Geneva framed the treaty lapse as a matter of U.S. sovereignty and negotiating leverage.

“The treaty placed unilateral constraints on the United States that were unacceptable,” Thomas G. DiNanno said in Geneva as he outlined the administration’s position.

Thomas G. DiNanno, Under Secretary for Arms Control

The president’s previous public remarks about testing—made in 2025—have been cited by aides as a policy driver.

President Trump said last year he wanted to resume detonations “on an equal basis” with China and Russia, a line officials reference when discussing parity arguments.

Donald J. Trump (public statement, 2025)

Unconfirmed

• No official has confirmed the number of warheads the administration might redeploy from storage to deployed forces.
• The specific type, yield, location or timeline of any contemplated explosive test has not been disclosed.
• It is unconfirmed whether Moscow or Beijing will respond with reciprocal deployments or tests and what form such responses might take.

Bottom Line

The expiration of New START has opened a window in which the United States is publicly exploring options that would widen the nuclear posture gap with the past three decades: redeploying stored warheads and resuming explosive testing are both back on the table. These are high-impact decisions that would require clear policy justifications, interagency and allied consultations, and likely congressional debate before moving from planning to execution.

Observers should watch for concrete signals in the coming weeks: administration decisions on force-sizing, certification pathways, and any formal orders to the NNSA or military services. Equally important will be diplomatic responses from Russia, China, NATO allies and partners in Asia—responses that will determine whether this period becomes a new arms competition or a leverage point for a broader, multilateral agreement with verifiable limits.

Sources

• The New York Times (news report)
• U.S. Department of State — New START overview (official)
• National Nuclear Security Administration (NNSA) (federal agency)