President Donald Trump is implementing a new-old defense strategy inspired by the one that has been implemented by President Ronald Reagan.

President Trump announced his defense strategy "Peace Through Strength" doctrine, in his campaign for a second presidential term. The core belief is that overwhelming, unambiguous U.S. military superiority—coupled with a demonstrated willingness to use force unpredictably—is the best way to deter adversaries and avoid costly wars. It is inherently transactional, unilateralist, and threat-centric. It prioritizes clear "wins," burden-sharing from allies, and views military power as the primary tool of statecraft, less integrated with diplomacy and development.

This Reagan-era revived strategy radically differs from that of President Joe Biden, which was centered on the concept of "Integrated Deterrence." This meant seamlessly combining U.S. military capabilities with all tools of national power—diplomacy, technology, economic statecraft, intelligence—and tightly coordinating with allies and partners to confront challengers. It was multilateralist and focused on strategic competition across domains (cyber, space, economics), not just military confrontation. The National Defense Strategy (2022) framed China as the "pacing challenge" and Russia as an "acute threat."

Washington, Beijing, Moscow

While China remains the top long-term strategic competitor/rival/adversary, there is a Trump pronounced and immediate focus on a resurgent "Axis" including Russia, China, Iran, and North Korea, all seen acting in coordinated hostility. The language is more confrontational, treating them as an alliance of enemies rather than separate challenges.

Under Biden, China was the Pacing Challenge and Russia the Acute Threat. The strategy was sequenced and differentiated. China's comprehensive long-term competition was the primary focus, requiring a global posture rebalance to the Indo-Pacific (though disrupted by Ukraine). Russia was the most immediate military threat to European security, requiring reinforcement of NATO's eastern flank. Iran and North Korea were "persistent threats" managed through containment and diplomacy.

Alliance Management

Trump views alliances as financial transactions. The expectation is for allies to immediately and substantially increase defense spending, far beyond NATO's 2% GDP target, and to purchase U.S. military hardware. There is a threat of conditional security guarantees, including withdrawing U.S. troops or refusing to defend allies deemed to be "delinquent." This creates intense short-term pressure but risks eroding long-term trust and interoperability.

In contrast, Biden had sought to revitalize and expand alliances (NATO, AUKUS, partnerships in the Indo-Pacific). Burden-sharing was encouraged, but within a framework of shared democratic values and strategic interests. The goal was to create a dense network of partnerships to out-compete China and contain Russia, viewing U.S. forward presence as an investment in a stable, rules-based order.

Force Posture, Deployment

Trump's strategy is flexible, unpredictable, and cost-effective. Expected moves include reduced permanent forward presence and more rotational deployments over large, fixed bases, to keep adversaries guessing and reduce costs.

It focuses on naval and air power and prioritizes submarine and air force expansion for power projection, over large, permanent Army garrisons abroad.

It also explicitly ties troop levels in places like South Korea, Japan, and Europe to host nation financial contributions and trade concessions.

Here also the strategy differs from Biden's, which was stable, predictable, and regionally tailored, focusing on enhancing European posture by permanently stationing more troops, headquarters, and capabilities in Eastern Europe post-Ukraine invasion.

Troop deployment was reinforced by investments in integrated bases for joint operations in Australia, the Philippines, and Guam, and increased naval patrols and military exercises with partners.

Nuclear Weapons, Strategic Deterrence

Whereas Biden was committed to modernization, but solely to maintain a credible deterrent, Trump embraced the modernization and expansion of the nuclear arsenal with an openness to resume testing. The goal is to achieve such overwhelming superiority that it deters any nuclear coercion by Russia or China.

Use of Force, Decision-Making

While Biden took a deliberate and calculated path to decision making when it came to the use of force, Trump chose to be unpredictable and decisive.

He embraced strategic ambiguity to keep adversaries off-balance. Major decisions are likely to be highly centralized in the White House, with less deference to the Pentagon's risk assessments.

Technology, Future Warfare

While Biden prioritized advanced tech through the lens of collaborative development with allies, Trump's strategy focuses on accelerated procurement of existing advanced systems such as, F-35s, Virginia-class subs, and disruptive technologies like hypersonic missiles, drone swarms, and AI-enabled warfare. There's likely to be a push for a "Space Force" on steroids and a national missile defense shield. Innovation may be driven more by private sector competition and less by joint, allied roadmaps.

Strategic Implications

Trump's strategy presents a more unpredictable and confrontational front in the face of adversaries like China, Russia, and Iran. It could deter aggressive military actions due to fear of disproportionate response, but it may also accelerate adversary alignment, and risks miscalculation if redlines are ambiguous.

As for allies, it creates immediate political and financial strain. Allies face stark demands that could fracture cohesion. While some may increase spending, the transactional approach damages the collective defense ethos.

Implications for conflict zones are obvious as the strategy represents a decisive shift from Biden's "as-long-as-it-takes" support to a transactional, condition-based approach demanding European financial carry and pushing for rapid negotiation, likely on terms favoring Russia's territorial gains.

For Taiwan the strategy allows increased military sales and visible support, but keeps deliberate ambiguity on the precise U.S. response to an invasion.

As for the Middle East, Trump's strategy offers a much tougher, potentially pre-emptive stance against Iran and its proxies, with higher risk of direct U.S.-Iran conflict.