Trump and the New Era of U.S. Nuclear Ambiguity

It seems that the second Trump administration has decided not to conduct a Nuclear Posture Review (NPR)—a process that results in the articulation of the United States’ (U.S.) national nuclear strategy. This represents a clear shift from decades of precedent and risks dangerous ambiguity at a critical time. Skipping the NPR could reflect several motivations: avoiding politically contentious debates over nuclear doctrine, or prioritizing modernization of the U.S. arsenal over the cumbersome interagency review process. But it leaves allies and adversaries guessing about U.S. nuclear doctrine at a moment when clarity is essential for nuclear deterrence.

This isn’t an unfounded concern. Research shows how uncertainty in nuclear strategy can fuel escalation—from the Pentagon’s 1983 “Proud Prophet” wargame, where unclear nuclear signaling drove players to escalate, to recent studies that show how ambiguity can spur arms races, increase inadvertent escalation, and even reinforce “enemy images” that influence and distort critical decision-making. In today’s environment—with Russia rattling its nuclear saber in Ukraine, China rapidly expanding its arsenal, North Korea escalating tests, and Iran edging closer to the nuclear threshold—such misperceptions could tip already fragile crises into open conflict.

The Nuclear Posture Review defines the role of nuclear weapons in U.S. national security. It details existing nuclear capabilities, plans for future development, and potential employment scenarios. Unlike the National Security Strategy—which Congress requires each administration to publish—the Nuclear Posture Review is not mandated by law.

Traditionally released early in a president’s term, the Nuclear Posture Review guides force posture, modernization programs, and declaratory policy. Its development requires an extensive, often complex interagency process involving the Defense and State Departments, the National Security Council, and the intelligence community. The NPR helps to deter adversaries, reassure allies, shape perceptions of U.S. resolve, and provide frameworks to support arms control and nonproliferation efforts. Without it, allies and adversaries are left to piece together doctrine from scattered references and unofficial statements, undermining the credibility of U.S. strategic commitments.

Trump’s second term has departed from traditional policymaking, emphasizing executive action, shrinking the National Security Council, and placing it under the Secretary of State rather than the National Security Advisor. This shift towards centralized control potentially sidelines formal strategy documents in favor of flexible, behind-closed-doors policymaking.

Some former officials suggest that a short executive order could serve as a substitute. For that to be effective, however, it would need to articulate U.S. nuclear doctrine, define modernization priorities, and send credible signals to both allies and adversaries. Historically, those signals have meant clear assurances of extended deterrence and a reaffirmation that U.S. capabilities will back allied security commitments, while at the same time providing adversaries with unambiguous deterrent messaging that outlines both the consequences of aggression and the limits of U.S. nuclear use. Anything less risks exchanging strategic clarity for ambiguity, at a time when cohesion and predictability are most needed.

Trump’s decision to bypass the Nuclear Posture Review process in his second term can be understood in two ways: either as a disruption that breaks from decades of precedent and the traditional interagency policy process, or as a continuation of the doctrine laid out in his 2018 Nuclear Posture Review. His first-term NPR signaled a shift toward an expanded role for nuclear weapons in U.S. strategy and the development of new capabilities to provide more flexible deterrent options and counter an aggressive Russia. Notably, it opted for ambiguity in place of transparency on critical matters such as whether the U.S. would ever use nuclear weapons first in a conflict. With ambiguity around the second Trump administration’s posture toward nuclear strategy, the absence of a clear doctrine leaves allies and adversaries left to interpret U.S. intentions and capabilities through guesswork rather than guidance.

This policy vacuum is particularly dangerous given the rapid evolution of global threats. Russia has suspended participation in the New Strategic Arms Reduction Treaty and continues to rattle its nuclear saber during its war on Ukraine. China is expanding its nuclear arsenal at an unprecedented rate, while North Korea continues to expand its nuclear arsenal. Iran’s nuclear program is also advancing unchecked as international negotiations fail and Israel escalates tensions with targeted strikes on Iranian facilities. In this environment, the absence of declaratory doctrine could appear less like strategic ambiguity than strategic drift.

Trump’s 2018 Nuclear Posture Review emphasized nuclear flexibility and modernization—advocating for low-yield warheads for Submarine-Launched Ballistic Missiles (the W76-2), nuclear-armed sea-launched cruise missiles, and an expanded set of conditions for nuclear use, including “non-nuclear strategic attacks.” It reflected a worldview that prioritized deterrence through strength, de-emphasized traditional arms control, and advanced the notion of an unrealistic trilateral agreement with China and Russia.

Today’s changed security environment demands updated signaling. The administration has not yet clarified how it intends to distance itself from the 2022 Biden Nuclear Posture Review, which emphasized arms control, nonproliferation, and a narrower role for nuclear weapons, or how it will address emerging challenges, such as multi-domain threats, advanced technologies, and allied concerns over extended deterrence. The administration may use the forthcoming National Defense Strategy to articulate nuclear guidance in lieu of a formal NPR. But it remains to be seen whether this will provide the doctrinal detail and interagency consensus typically associated with a full Nuclear Posture Review.

In the absence of a Nuclear Posture Review, observers may turn to other documents, like the 2023 bipartisan Strategic Posture Commission (SPC) report, to fill the gap. The SPC warned of a two-peer nuclear threat environment—Russia and China—for the first time in its history, calling for enhanced force posture, improved missile defense, and strengthened deterrence frameworks. While these recommendations overlap in some areas with the 2018 Nuclear Posture Review’s emphasis on modernization and flexibility, the SPC report reflects a broader strategic recalibration—one that prioritizes resilience, integrated deterrence, and cross-theater coordination.

Relying on these other frameworks in lieu of a formal Nuclear Posture Review risks muddying the strategic waters. The SPC report and past Nuclear Posture Reviews serve different purposes and audiences. Without an updated and authoritative guide to synthesize and direct U.S. strategy, the field becomes crowded with potentially conflicting signals. This lack of coherence leaves allies uncertain, adversaries opportunistic, and the United States vulnerable to misperception and miscalculation in a rapidly evolving nuclear landscape.

Project 2025, a conservative policy agenda developed by the Heritage Foundation and other right-wing think tanks, is often seen as a reliable blueprint for the administration’s nuclear thinking. Thus far, the administration has closely followed Project 2025’s guidance across a range of national security domains, and nuclear policy appears to be no exception. The plan calls for withdrawing support for the Comprehensive Nuclear-Test-Ban Treaty, preparing to resume nuclear testing, developing new warheads and advanced delivery platforms such as hypersonic missiles and road-mobile Intercontinental Ballistic Missiles, defunding non-nuclear research at national laboratories, and prioritizing nuclear superiority over arms control engagement.

Interestingly, Project 2025 and the 2023 Strategic Posture Commission Report share a foundational belief in the need for a more robust and responsive U.S. nuclear posture. Both acknowledge the growing challenge of a two-peer environment involving China and Russia. But they diverge sharply in tone, emphasis, and philosophy. The bipartisan Commission situated its recommendations within a broader strategic framework that includes arms control, alliance coordination, and deterrence stability. Project 2025, by contrast, downplays arms control and advances a unilateral approach focused on nuclear dominance and testing readiness. Where the Commission emphasizes the importance of credibility and reassurance in extended deterrence, Project 2025 promotes a more hardline vision that risks undermining international norms and allied trust.

These competing approaches to managing 21st-century nuclear risks will determine not only U.S. deterrence posture but also the broader credibility of its alliances and arms control commitments. Moreover, implementing Project 2025 recommendations without the guidance and constraint of a formal Nuclear Posture Review would signal a fundamental shift in nuclear policy and the role nuclear weapons play in U.S. grand strategy.

The extended deterrence architecture in East Asia and Europe relies on credible U.S. commitments in both capability and articulation. Even as allies invest heavily in conventional defense, they increasingly expect the U.S. nuclear umbrella to be backed by modernized and clearly communicated nuclear strategies.

Moreover, recent U.S. statements have called into question long-standing alliance commitments, standing in stark contrast to plans to deploy the sea-launched cruise missile nuclear variant, which is intended to bolster assurance for allies by providing flexible, theater-based deterrence options. The contradiction between verbal disengagement and material reassurance deepens strategic ambiguity, increasing the risk of misperception among both allies and adversaries. In nuclear deterrence, such mixed signals can have far-reaching and unintended consequences.

The absence of a formal doctrine could also blur the boundaries of what constitutes “strategic communication.” If the Nuclear Posture Review is abandoned and replaced with something as brief as an executive order, where does the line get drawn? Could a tweet qualify as nuclear doctrine? A speech at a rally? Without the structure and deliberation of a formal review, even casual remarks risk being misread as strategic signals. In such a vacuum, every informal utterance carries outsized weight and outsized consequences. A tweet may be legally irrelevant, but in the absence of a formal Nuclear Posture Review, it could be read by allies or adversaries as a de facto statement of intent.

In the nuclear domain, words carry special weight—as signals of posture, policy, and power. And when that power is exercised without clarity, deliberation, or restraint, the world doesn’t get safer. It gets more dangerous. The question now is whether the United States can afford the global risks of leaving nuclear policy to ambiguity and improvisation.