Since the 2014 wake-up call in Crimea, U.S. deterrence thinking has shifted from single-theatre assumptions toward acknowledging a late-Biden-era “two-peer competitor” environment. Nuclear modernisation programmes began before that shift and may now be mismatched to the threat landscape. In parallel, there is an explicit recognition of the need for greater burden sharing (already visible in NATO discussions and budget increases), and this expectation extends to Asia. Strategy is trending toward tighter integration across domains and types of conflict, building on multidimensional planning while knitting efforts more deeply with allies, even as rapid U.S. advances in cyber and space could complicate seamless integration. The main drivers of change include the rise of the two-peer problem and the “pivot to Asia”; overlapping timelines for China’s nuclear modernisation, a potential Taiwan contingency, and China’s consolidation as the closest economic competitor; a Chinese buildup that makes U.S. coercion less certain while expanding Beijing’s coercive options; and an increased likelihood of Russian nuclear use. Cooperative or opportunistic coordination among adversaries (Russia-China, Russia-DPRK, Iran, etc.) are of particular concern, and arms-control prospects are currently dim, reducing avenues to constrain opponents collectively.
The U.S. is likely to increasingly have to address the two-peer problem through its deterrence strategy. A central question is whether the U.S. and allies can realistically sustain conventional superiority given costs and political will; if not, nuclear forces sized and configured for alternative strategies may differ from those needed to manage simultaneous nuclear escalation from both Russia and China. If a U.S.-China conflict draws resources to the Indo-Pacific and Europe cannot sufficiently rearm conventionally to deter Russia, Washington could lean more on its nuclear posture in Europe to backstop alliance shortfalls. Capabilities that support allies will differ by theatre, but promptness of response will be universally important. Targeting approaches may also need to adapt; advocates of moving away from counterforce warn it is destabilising and, in a two-peer setting, could fuel arms racing by undermining the plausibility of damage limitation; others argue counterforce can still help prevent limited nuclear use from widening into existential exchange, even as regional counterforce becomes more dispersed and demands larger strikes.
The real debate, then, is how much counterforce capability is necessary, and whether to prioritise it against Russia, China, or both (simultaneously or sequentially), given extended-deterrence commitments and finite resources across the conventional-strategic spectrum. The credibility of extended deterrence during any U.S. conventional drawdown will hinge on the tone and nature of that drawdown.
Four broad options are in view:
- Maintain robust conventional and nuclear forces to deter both peers simultaneously.
- Increase reliance on nuclear forces to cover conventional gaps.
- Keep alliance commitments while reprioritising where to accept risk.
- Pivot fully to Asia and ask Europe to shoulder its own burden.
The fourth is potentially more likely, although it should not reassure European allies; it could spur “friendly” proliferation. Finally, a prospective “Golden Dome” of missile defence could shape allied and adversary behaviour: its effects are uncertain, it might provoke pre-emptive attacks intended to derail the system, and, if highly effective, it could increase the appeal of counterforce targeting against strategic threats.