Geopolitics and public health: Europe under the shadow of the U.S. National Security Strategy.

The 2025 U.S. National Security Strategy marks a major shift toward a narrowly defined "America First" agenda with significant implications for Europe and its health systems. It reframes global public goods, including disease surveillance, migration governance, and climate action, as burdens rather than shared responsibilities, while prioritising hard power, economic nationalism, strict border control, and fossil fuel expansion. Europe is urged to increase defence spending to 5% of GDP and reduce regulatory and welfare commitments, thereby creating fiscal pressures that risk crowding out investment in health and social care. Its rhetoric on migration, culture, and declining birth rates aligns with and empowers far-right movements, potentially accelerating welfare retrenchment and undermining access to care for migrant and marginalised populations. This Viewpoint analyses the implications of the 2025 U.S. National Security Strategy for public health and health systems in Europe, with particular attention to welfare, migration, climate, and multilateral cooperation. A weakened WHO, reduced U.S. multilateral engagement, and more transactional transatlantic relations threaten global health security. Europe must safeguard health systems, equity, and the multilateral global order.