Charting the New Nuclear Age

Key Findings and Recommendations

Finding

Russia and China do not need to collaborate to create serious deterrence challenges for the United States. In the TTX, Russia and China pursued independent, opportunistic actions that collectively strained U.S. forces without requiring coordination, joint operations, or shared intelligence.

Recommendations

• The Department of War (DoW), Office of the Undersecretary of War for Policy (OSW-P), DTRA, Joint Staff J-8, U.S. Strategic Command (STRATCOM), Global Strike Command, U.S. European Command, and U.S. Pacific Command should apply the scenario framework to generate additional sequential 2NP scenarios and explore these through structured analysis and TTXs. The baseline scenarios created for this project provide a starting point, but additional variants are needed to test different combinations of adversary actions, timing, and escalation levels.
• The DoW should resist the impulse to focus exclusively on the most stressing scenario of simultaneous, high-intensity conflicts requiring deep Sino-Russian coordination. Opportunistic, sequential aggression is more likely because it does not require deep trust and coordination between Beijing and Moscow and, as this analysis demonstrates, can impose substantial costs on the United States even without formal cooperation between the two adversaries.

Finding

Protracted, lower-level simultaneous conflicts can pose serious challenges and are more likely than concurrent, high-intensity wars. During the TTX, each 2NP adversary pursued calibrated, steady escalation below the threshold of direct military engagement with the United States. This included gradually expanding blockades and engaging in escalatory military harassment without clear-cut aggression—constraining U.S. response options and complicating American decision-making. The narrow range of options available to roll back adversary gains while preventing further escalation left U.S. players in a persistent strategic bind.

Recommendations

• The DoW should challenge assumptions that great power crises and moderate intensity conflicts will be short and decisive. The nuclear capabilities of all parties create strong incentives for escalation management that increases the likelihood of protracted conflict. The United States must plan for sustained operations across two theaters simultaneously.
• OSW-P, the Joint Staff J-4, and U.S. Transportation Command should assess the ability to swing forces between theaters under realistic conditions, including degraded information environments, cyberattacks on logistics networks, and competing demands for key assets from homeland defense and nuclear deterrence missions.
• OSW-P should examine how space and cyber capabilities—which are less constrained by distance—can bolster deterrence and warfighting in two theaters simultaneously to compensate for conventional weapons systems that take time to deploy.

Finding

Nuclear signaling is particularly difficult when facing two separate adversaries, and the United States currently lacks the tools and practice to credibly communicate resolve across the spectrum of conflict in both theaters at once. In the TTX, Red assessed that Blue's nuclear signaling was insufficient to alter its decision-making. Strategic bombers were the only visible, deployable nuclear capability in the Pacific and were overextended between conventional strike and nuclear signaling missions. Military actions to ready nuclear delivery platforms were not paired with direct strategic communications from senior leaders, and their intent was not clearly received by either adversary.

Recommendations

• The DoW should explore options for acquiring theater-level nuclear forces, such as ground-based missiles, tactical aircraft, and surface ships, which can be deployed forward, particularly to the Pacific, and that are visible enough to be useful for signaling. The current reliance on strategic bombers for both conventional operations and nuclear deterrence would likely overstretch the bomber and tanker force.
• OSW, STRATCOM, and the Air Force could increase stealth bomber and airborne refueling aircraft procurement to expand the U.S. military’s capacity to simultaneously conduct conventional deterrence and warfighting, and nuclear signaling and operations against two peer adversaries.
• The Joint Staff and the services should increase training and exercising of U.S. forces for nuclear operations so that they can be employed quickly and effectively to signal resolve and demonstrate resilience on a possible nuclear battlefield. The U.S. military has fallen out of practice with explicit nuclear signaling, and this gap was evident throughout the exercise.
• DTRA could conduct TTXs focusing on theater-level nuclear forces and integrated conventional and nuclear capabilities with senior leaders that build familiarity with the strengths, weaknesses, and risks of different signaling options and require them to tightly link strategic communications to military actions.

Finding

Homeland defense and nuclear deterrence missions compete with conventional operations for the same limited, high-demand assets. As the 2NP scenario escalated, U.S. Northern Command, STRATCOM, and the theater combatant commands competed for tankers, bombers, and airborne early warning aircraft. The existing force structure was not adequate to meet these mission demands simultaneously, and every deployment decision in one theater directly weakened posture in the other.

Recommendation

• OSW-P and the Joint Staff should evaluate the adequacy of the Joint Force's high-demand, low-density assets against the requirements of simultaneous 2NP operations, including concurrent homeland defense, nuclear deterrence, and theater conventional missions and identify specific shortfalls and investment priorities.

Finding

The role of allies in 2NP scenarios requires more exploration: What will be needed to reassure them, what capabilities can they contribute, and would they accept a sequenced U.S. response that prioritizes one theater over the other? In the TTX, Blue players sought to defer a full response to Russian aggression in Europe while focusing on the Pacific, but it was unclear that European allies would be able to hold their own or would accept delayed American engagement even in a limited contingency. This could prompt them to make additional investments in conventional capabilities, which would be welcomed, but could also spur undesirable nuclear proliferation. Maintaining strong cooperation between American allies and partners in 2NP scenarios sends a powerful deterrent signal and highlights the relative isolation of Russia and China compared to the coalition arrayed against them.

Recommendations

• OSW-P should initiate structured consultations with Pacific and NATO allies on 2NP contingencies, focusing on what capabilities they could contribute, what assurances they would require, why this level of preparation may be necessary, and what allies can do to improve their ability to defend with limited U.S. assistance. These consultations should proceed at the working level for discussions of specific capabilities, which can be reinforced by strategic-level discussions for issues dealing with assurance.
• When possible, the DoW should incorporate allies into future 2NP tabletop exercises to gain direct insight into their perspectives, particularly on escalation management, access, basing, and overflight, restrictions on offensive operations, and the demands they would place on the United States for extended deterrence guarantees.
• The Joint Staff and DTRA should conduct additional analysis on the issue of cross-theater credibility to include running TTXs focused on allies’ and Reds’ perspectives and reactions to this approach. Adversaries and allies alike must believe that the United States has not only the capability, but also the will to uphold its extended deterrence commitments. Strong U.S. action to defend an ally or partner in one theater could be read as a signal of broader American resolve to defend allies, but that inference is far from assured.

Introduction

The United States has entered a new nuclear era.¹ After the Cold War, Washington sought to reduce the role of nuclear weapons in its strategy and relied on conventional overmatch to deter and defeat aggression.² Its adversaries responded by investing in asymmetric capabilities, including anti-access area-denial systems and nuclear weapons. Now unconstrained by arms control agreements, Russia has modernized its strategic arsenal, developed exotic delivery systems to circumvent missile defenses, and maintains the world’s largest nonstrategic nuclear stockpile.³ Its 2022 invasion of Ukraine shattered assumptions that high-intensity conflict in Europe was a relic of the past, while its nuclear threats raised the specter of deliberate escalation, weakening the nuclear taboo.⁴ Meanwhile, China is in the midst of a strategic breakout, constructing new missile silo fields, fielding road-mobile intercontinental ballistic missiles (ICBMs), expanding theater delivery systems, and building low-yield warheads.⁵

Prior research by the Defense Program at the Center for a New American Security (CNAS) has traced the implications of these developments. Long Shadows surveyed the emerging multipolar nuclear landscape.⁶ Avoiding the Brink found that China’s expanding arsenal will provide it with coercive options that did not previously exist.⁷ Over the Brink demonstrated that protracted conventional conflict increases the risk of deliberate limited nuclear use.⁸ The United States now faces an “unprecedented” and “far more complex and challenging” nuclear environment, one that nuclear experts and former Biden administration officials Vipin Narang and Pranay Vaddi characterized as “a Category 5 hurricane of nuclear threats.”⁹

What makes this environment so dangerous is not only the capabilities of each adversary individually, but the prospect of facing both simultaneously or sequentially.¹⁰ Analysis of the two-nuclear-peer (2NP) challenge is at an early stage and there is a risk of focusing on the most stressing scenario: two simultaneous, high-intensity conflicts enabled by coordinated Sino-Russian action.¹¹ Opportunistic scenarios that feature sequential, uncoordinated aggression are more likely because they do not require a high degree of mutual trust and strategic commitment between Beijing and Moscow.¹²

The space between gray zone provocations and all-out war remains underexplored. This project was designed to widen the aperture by developing a framework that captures the full range of 2NP scenarios, then testing the framework through structured analysis and an exploratory tabletop exercise (TTX). The Defense Program at CNAS conducted this project for the Defense Threat Reduction Agency (DTRA) between 2025 and 2026. The team convened a workshop of nuclear, conventional, and regional experts; developed a scenario framework organized around the key variables that define a 2NP conflict; applied the framework to construct a scenario for a TTX; and ran the TTX once as an initial exploration of the problem. The findings and recommendations that follow identify areas that merit further analysis and testing rather than offering definitive conclusions.