Charged Affairs

By Mariam Kvaratskhelia | Rising Expert on National Security | October 7, 2025 | Photo Credit: Flickr

In early August, President Trump ordered two nuclear submarines to be deployed to unspecified “appropriate regions” in response to remarks by former Russian President Medvedev reminding Washington of Russia’s “doomsday” nuclear capabilities. It was never clarified whether the submarines were nuclear-powered or nuclear-armed, nor was their precise destination disclosed. This ambiguity was intentional—Trump was signaling resolve to Moscow, purposefully borrowing a trick from Putin’s own nuclear playbook.

Strategic, deliberate, calculated—these are the words often used to describe a long-lasting pillar of U.S. nuclear deterrence: ambiguity. As Thomas Schelling famously wrote, deterrence is “the threat that leaves something to chance.” Avoiding explicit warnings or rigid thresholds injects uncertainty into an adversary’s calculations, compelling them to act with greater caution.

This is the logic behind the U.S. policy of strategic ambiguity: deliberately not stating when, why, and how the United States might use nuclear weapons. The ambiguity Trump employed in early August reflects an enduring tool of deterrence—stabilizing when applied in a limited way and targeted at an adversary that thrives on nuclear signaling, as Russia does.

But ambiguity is a double-edged sword: while it clouds an adversary’s calculations, it can also unsettle allied confidence or create incentives for preemption. In today’s more complex environment—marked by three major nuclear powers, the erosion of arms control, and the spread of emerging technologies—overreliance on nuclear ambiguity may introduce risks beyond an acceptable level to Washington.

A Brief History of Ambiguity

From the early Cold War to the present, U.S. presidents have calibrated nuclear declaratory policy to strike a balance: signaling red lines with just the right amount of clarity to deter, and just the right amount of ambiguity to keep adversaries guessing. Ambiguity gave Washington flexibility to respond on its own terms in a potential conflict. It also denied adversaries the ability to exploit rigid thresholds by acting just below them.

The Eisenhower administration’s “massive retaliation” doctrine threatened an overwhelming nuclear response to an unspecified range of Soviet provocations—deterring through fear of disproportionate escalation. Later doctrines, such as NATO’s “flexible response” strategy of the late 1960s, leaned even more heavily on ambiguity, rejecting a no-first-use policy and planning for possible early or limited use of nuclear weapons. The goal was simple: denying the Soviets confidence at any rung of the escalation ladder.

But ambiguity also carried risks: it unsettled allies, blurred the line between conventional and nuclear conflict, and could even incentivize preemption—creating precisely the kind of uncertainty that could have sparked escalation rather than prevented it. 

Where We Are Today

The United States remains committed to strategic ambiguity. The 2018 Nuclear Posture Review underscored that nuclear weapons would be used only under “extreme” circumstances and in defense of “vital” interests. The exact meaning of these terms remains deliberately undefined. As Alex Mazzone points out, even senior strategists “do not truly know what constitutes an extreme circumstance until they are placed in a situation that warrants such an evaluation.” There’s a practical reason for this, too: as a global superpower, it is nearly impossible to specify everything that constitutes a “vital” interest for the United States—there are simply too many.

The 2023 Strategic Posture Commission report reaffirmed strategic ambiguity as one of six fundamental tenets of U.S. nuclear policy. The logic is the same: ambiguity complicates adversary decision-making and preserves the option of first use.

Yet today, ambiguity operates in a very different political environment. During the Cold War, it was aimed at deterring a single nuclear peer within a system bounded by arms control guardrails. Now the United States faces two such peers. China is rapidly expanding its arsenal, casting doubt on the credibility of its declared no-first-use policy. Meanwhile, Russia wields its nuclear arsenal as a tool of coercion in Ukraine and beyond—threatening use, raising alert levels, suspending participation in the New START Treaty, and deploying tactical weapons in Belarus. Ambiguity that may stabilize one adversary may embolden the other—or encourage both to test Washington’s resolve simultaneously.

At the same time, the United States remains far more transparent about its capabilities than Moscow or Beijing—out of necessity, to reassure over 30 allies and partners who depend on U.S. extended deterrence. These alliances are both a strength and a challenge: ambiguity may deter adversaries, but too much of it risks increasing allied anxiety over U.S. nuclear guarantees.   China and Russia are not burdened by such alliance commitments, allowing them greater opacity in both doctrine and capabilities.

Exercising Ambiguity in A Riskier World

Today’s global security environment is more volatile than Cold War bipolarity. The United States now faces two nuclear peers—Russia and China—amid eroding arms control frameworks with the former and the absence of any with the latter. The Iran nuclear deal nears collapse, while U.S. allies such as South Korea openly debate developing indigenous nuclear capabilities.

Meanwhile, novel technologies, like dual-use hypersonics, blur the line between conventional and nuclear capabilities. Integration of artificial intelligence into command, control, and communication heightens the risks of false alarms and compressed decision timelines. These technologies introduce further uncertainty into already unstable security dynamics.

In this context, the risks of strategic ambiguity may outweigh its deterrent value. To be clear: ambiguity remains a valuable tool, and one that the United States could comfortably rely on in a more predictable global environment. But in a world where uncertainty is the defining feature of the international system, overreliance on ambiguity risks fueling misperception and miscalculation, triggering inadvertent escalation, and heightening alliance anxiety.

The challenge for policymakers is not whether to preserve ambiguity, but how to adapt it. That means clearer signaling—for example, underscoring that the nuclear threshold remains high and that U.S. efforts are focused on keeping it that way—which can ease tensions, reassure allies, and guard against deterrence failure.

In an era marked by great power competition, rapid technological change, and weakened arms control, policymakers must ask: where does ambiguity deter—and where might it invite aggression?

Mariam Kvaratskhelia is a Washington-based policy analyst specializing in emerging technology, nuclear strategy, and outer space security. She is a double graduate of Georgetown University’s School of Foreign Service and a National Security Rising Expert with Young Professionals in Foreign Policy.