“Modern, flexible, robust, resilient” were among the four most commonly used words in Trump’s 2018 Nuclear Posture Review (NPR). With his return to the White House, many expected to see a similar vocabulary guide the direction of U.S. nuclear doctrine. Yet, recent statements from the Oval Office suggest a potential shift—one that emphasizes arms control and defense budget reductions over the pursuit of new nuclear capabilities. This would mark a notable reorientation from both Trump’s first-term military posture and traditional Republican foreign policy. It is unclear whether these remarks reflect an internal debate, a genuine policy recalibration, or a deliberate negotiation tactic—strategic ambiguity in action. Even if pursued seriously, such a pivot would likely face resistance from congressional Republicans and run up against the Strategic Posture Commission’s recommendations for a more assertive U.S. deterrence posture. Background: Strategic Landscape Shifts From Obama to Trump’s First Term The threat assessment of the 2018 NPR was unique, as it formally acknowledged the emergence of a new adversary on the horizon: China. Previous administrations had largely downplayed this threat, given that China lacked the nuclear capabilities sufficient to challenge U.S. forces the same way the Soviet Union (and later Russia) did. This marked a significant departure from the strategic assumptions that had shaped U.S. nuclear policy over the previous decade. The Obama administration’s approach, for example, centered on reducing the role of nuclear weapons in national security. The phrase “a world without nuclear weapons” became the cornerstone of his nuclear strategy, emphasizing nonproliferation, arms control, and restraint. Obama’s 2010 NPR embodied a “minimum” or “easy” deterrence school of thought: the belief that understanding necessary requirements for stable mutual deterrence is easy, and that strategic stability can be maintained at reduced force levels. Trump rejected this approach, favoring a “maximum” or “difficult” deterrence stance—one that supports a robust triad, greater force diversity, and an expanded role of nuclear weapons in U.S. defense strategy. For the first time in history, the U.S. declaratory policy recognized the presence of two nuclear-armed competitors—a geopolitical reality that dramatically complicated the American defense calculus. Besides this, the 2018 NPR put a magnifying glass over a key gap of the Obama-negotiated New START: its exclusion of non-strategic, or tactical, nuclear weapons. Russia’s ten-to-one advantage over the U.S. in this category underscored the need for a more diverse and flexible U.S. arsenal that would provide the President with a wide range of response options across all levels of conflict. In response, the Trump administration took several key steps: it upgraded F-15 dual-capable aircrafts to nuclear-capable F-35s (designed to deliver the 100 forward-deployed B61 gravity bombs in Europe); it modified a limited number of submarine-launched ballistic missiles (SLBMs) to carry low-yield W76-2 warheads; and it introduced a modern nuclear-armed sea-launched cruise missile (SLCM-N). Together, these initiatives aimed to reassure allies by demonstrating that the U.S. possessed both the resolve and assured response capability to react to potential regional nuclear use by its adversaries. Biden, Congressional Pushback and Strategic Posture Commission The Biden administration returned to an Obama-era nuclear doctrine with a few notable changes. It removed “hedging against an uncertain future” as a formal role of nuclear weapons, introduced “integrated deterrence” as a whole-of-government approach to security, and defined the primary role of nuclear weapons as deterring a strategic nuclear attack against the U.S. and its allies. In line with this shift, the 2022 NPR canceled the SLCM-N program, citing redundancy with other capabilities such as the W76-2 low yield SLBM, the long-range standoff missile (LRSO), and dual-capable F-35s. The marginal utility of SLCM-N was deemed insufficient to justify its cost. However, Biden’s stance on SLCM-N faced congressional pushback. The bipartisan Strategic Posture Commission assessed that the U.S. needs a larger and more diversified nuclear arsenal in order to address the two-peer threat. While not explicitly endorsing SLCM-N, the Commission report outlined requirements—survivability, variable yield, forward-deployment, and air defense penetration—that SLCM-N uniquely meets. Congress ultimately overruled Biden’s cancellation, mandating the Department of Defense to reinstate the SLCM-N program and fund its W80-4 ALT warhead under Section 1640 of the FY2024 National Defense Authorization Act (NDAA), with the goal of achieving initial operational capability by 2034. Implications for Europe European allies have expressed concerns over a second Trump presidency, fearing it could strain transatlantic relations. During his first term, Trump famously declared the European Union a “foe” and asserted that U.S. commitment to NATO’s Article 5 mutual defense clause should be contingent on allies meeting their defense spending obligations. His return to the administration has reignited fears that Washington might retreat from its post-WW2 role as Europe’s principal security guarantor. Germany’s Chancellor-elect Friedrich Merz warned that the U.S. is becoming “largely indifferent to the fate of Europe,” suggesting that Berlin may need to instead turn to Britain and France for extended nuclear deterrence. Yet, two crucial realities are often overlooked in European discourse. First, European allies have voiced similar anxieties in the past with little resulting action. Former Chancellor Angela Merkel made comparable statements in 2017, but Europe’s security policy saw no meaningful change despite calls for reorientation. If Europe is serious about pursuing strategic autonomy, its urgent calls for increased military spending must be backed by action—something that has been long overdue, with or without Trump’s return to the White House. Second, Trump’s first-term defense policies suggest that fears of “nuclear abandonment” of Europe are overstated. Despite tough rhetoric and threats of U.S. withdrawal from NATO, Trump’s first term saw a significant rise in allied defense spending and a bolstered U.S. military presence in Europe via NATO’s Enhanced Forward Presence (eFP) and European Deterrence Initiative (EDI). The Trump administration also developed new low-yield nuclear systems and maintained forward-deployed gravity bombs in five NATO countries—including up to 20 in Germany. Unless the United States withdraws these assets or exits NATO altogether—neither of which is supported by current policy decisions made in Washington—fears of a U.S. retreat from its extended deterrence commitments are divorced from geopolitical realities. In fact, as recently as February 2025, Trump reaffirmed his support for NATO’s Article 5 provision for mutual defense. Furthermore, U.S. policymakers understand the strategic risks of removing nuclear forces from Europe. Doing so could open the door to indigenous nuclear proliferation or an increased reliance on British and French nuclear forces—developments that would have significant implications for the global nonproliferation regime. Though Paris and London may signal a willingness to extend their nuclear umbrella to other European nations, their arsenals are smaller and nuclear doctrines more constrained, making them ill-suited to fully replace U.S. extended deterrence in Europe. These forces supplement, not substitute, American military presence on the continent. Additionally, extension of the Franco-British nuclear umbrella to other European countries does little to resolve what might be called the “New York-for-Paris Dilemma.” France’s decision to develop its own nuclear arsenal under President Charles de Gaulle was rooted in deep skepticism toward U.S. security guarantees. That same fundamental question persists today: would Macron be willing to trade Paris for another European capital? Extended deterrence, by its very nature, carries an element of ambiguity—regardless of who provides it. The disconnect between European leaders’ alarmist reactions and Trump’s first-term defense policies serves as a reminder that anxieties over U.S. security assurances to allies across the Atlantic are often more influenced by inflammatory rhetoric than by concrete changes in American policies, capabilities, or interests. Extended deterrence remains a key pillar of U.S. strategic posture, backed by broad bipartisan consensus. The current ambiguity may reflect internal policy debate or deliberate signaling—but there is little to suggest that the United States intends to fold its nuclear umbrella or close the chapter on transatlantic security. Implications for the Indo-Pacific Japanese officials voiced serious concerns after the U.S. retired nuclear-armed Tomahawk Land Attack Missile (TLAM-N) in 2010, with then-Prime Minister Shinzo Abe suggesting a NATO-style nuclear burden-sharing framework. Since retiring TLAM-N, the U.S. has relied almost exclusively on its strategic nuclear arsenal for deterrence in the Indo-Pacific—a declaratory policy far from robust. Neither China nor North Korea believe that the United States would be willing to employ strategic weapons (and risk an all-out nuclear war) in response to a limited nuclear or conventional attack on its Asian allies. In South Korea, 71% of citizens support the country’s acquisition of nuclear weapons, reflecting growing public concerns over regional security threats. President Yoon Suk-yeol has stated that, in order to counter North Korean aggression, South Korea may need to either pursue its own nuclear capabilities or have the U.S. re-deploy tactical nuclear weapons on the Korean Peninsula. Interestingly, research shows that greater trust in American security commitments correlates positively with public support for nuclear weapons. This indicates that pro-nuclear sentiment in South Korea stems less from doubt in U.S. credibility and more from a desire for an independent, visible, and flexible deterrence posture. Trump’s first term saw increased defense investments in the Indo-Pacific and support for regional nuclear capabilities, including the development of SLCM-N. While recent statements from the Oval Office signal a pivot toward arms control and defense budget cuts, this trajectory now appears less certain—but not fundamentally altered—given the continued rise of adversarial nuclear threats in the region. China remains resistant to arms control talks. It is rapidly expanding both its strategic and non-strategic nuclear arsenals, while also modernizing its triad and investing in advanced delivery systems. These developments underscore that Beijing views its nuclear posture as central to its long-term strategic competition with the United States. Some experts argue that a U.S. adoption of a No-First-Use policy could alleviate China’s fears of a disarming surprise attack and incentivize engagement; however, Trump is highly unlikely to endorse such an approach—even in light of his recent remarks. If anything, the scale and speed of China’s nuclear buildup only strengthen the case for a stronger U.S. deterrent posture in the Indo-Pacific. North Korea poses a similarly compelling challenge. It now possesses missiles capable of reaching the continental United States and has a history of horizontal proliferation—having transferred nuclear technology to countries like Pakistan and Syria. Most recently, North Korean leader Kim Jong Un has pledged to further expand his country’s nuclear arsenal. As Scott Sagan has argued, North Korea no longer presents a nonproliferation problem, but rather a deterrence one—a “Cuban Missile Crisis in slow motion.” Trump’s first-term policies reveal that his administration views the regime in Pyongyang primarily through a deterrence lens. Although the President has recently signaled openness to arms control and reductions, North Korea’s continued expansion may well prompt a return to his earlier, hardline “Fire and Fury” approach: a maximum pressure campaign defined by primary and secondary sanctions, military threats, and coercive diplomacy against Pyongyang. These strategic realities—China’s military buildup and North Korea’s destabilizing behavior—are likely to outweigh recent statements about force reductions, reinforcing the need for a credible U.S. deterrence posture in the Indo-Pacific. What’s Next for the U.S. Nuclear Posture While Trump’s return to the White House was initially expected to mark a renewed push for a hardline deterrence stance, his recent public remarks on arms control and defense spending cuts have introduced ambiguity into that trajectory. These statements may indicate genuine posture shifts or merely serve as exercises in strategic ambiguity. Either way, their translation into actual policy remains uncertain. Geopolitical realities in both the European and Indo-Pacific theaters—alongside congressional pushback and the Strategic Posture Commission’s recommendations—are likely to serve as guardrails against the administration’s turn toward “easy deterrence.” Many of the same obstacles that stalled Trump’s first-term attempt at trilateral arms control negotiations remain unresolved today—and in a sense, have only grown more complex. As the next NPR takes shape, the administration must grapple with difficult questions: What would it take to bring China and Russia to the negotiating table? Are trilateral arms control agreements feasible, given the disparities in arsenal size and composition among the parties? Should such talks be expanded to include Britain and France? Can the New START treaty be revived amid the ongoing war in Ukraine? Should future arms control frameworks include caps on non-strategic nuclear weapons and emerging technologies? And how can the U.S. reconcile calls for defense budget reductions with new investments in missile defense systems like the Iron Dome? Despite the uncertainty, one conclusion stands: the fundamental pressures shaping the U.S. nuclear posture—strategic competition, alliance relations, and domestic political realities—are still in place. The rhetoric may look different, but the core architecture of Trump’s first-term nuclear posture is likely to stay intact.