3.4 – Power and developments
3.6 – Comparative theories
The 2025 US National Security Strategy presents a recalibrated vision of America’s global role, foregrounding territorial security, economic resilience, and tighter control of its neighbourhood. It casts instability in the Western Hemisphere, large-scale migration, and transnational criminal networks as primary strategic concerns, and links national strength to domestic economic and technological capacity. The strategy outlines a more assertive interpretation of the “Monroe Doctrine”, arguing that safeguarding the Americas is a prerequisite for wider international engagement.
Its language on Europe departs from earlier US strategic documents. While acknowledging the value of European partners, it questions the continent’s long-term political cohesion and cultural confidence, asserting that internal European debates over identity, migration, and governance may weaken shared strategic purpose. The document suggests that future transatlantic cooperation will depend less on institutional habits and more on demonstrable convergence of interests and values. It also calls for Europe to shoulder a greater share of defence responsibilities and to adapt its security posture to align more closely with American priorities.
For European security, these shifts are far-reaching. Many European governments interpret the strategy as a sign that American commitment to collective defence is becoming more transactional and less unconditional. The NSS may therefore accelerate moves toward European defence integration, higher military spending, and diversification of diplomatic partnerships (which began earlier in the year following the Trump-Zelenskyy Oval Office argument). It also introduces uncertainty around long-term American engagement in deterring Russian aggression in Eastern Europe and supporting Ukraine, prompting European states to reconsider the degree to which their security can continue to rely on American guarantees.