All quiet on the eastern flank? Nato leaders fear they can no longer rely on US help if Russia attacks

What Happened

Eastern European NATO members are grappling with deepening doubts about whether the United States would honor its collective-defense commitment if Russia attacked, according to dozens of officials interviewed over the past 18 months. The anxiety crystallized in February 2025 when U.S. Defense Secretary Pete Hegseth told allies in Brussels that European security was no longer a priority and demanded that Europe pay for its own defense. At a subsequent lunch, German Defense Minister Boris Pistorius requested a timeline for a U.S. drawdown, alarming some allies who feared it would accelerate an American retreat. Days later, President Donald Trump humiliated Ukrainian President Volodymyr Zelenskyy during a televised White House meeting, and the administration briefly suspended intelligence-sharing with Ukraine, shattering assumptions about U.S. reliability. In May 2025, Undersecretary of State Thomas DiNanno, asked directly in Tallinn whether U.S. troops would fight for the Baltic states, avoided a clear 'yes,' reinforcing fears. The mood has shifted from cautious approval of U.S. spending demands to profound unease about a transatlantic security rupture.

Key Actors

Why It Matters

The erosion of trust in U.S. security guarantees threatens the foundation of NATO's eastern flank, potentially emboldening Russia to test Article 5. A perceived American retreat forces European allies to accelerate independent defense capabilities, risking a fracturing of the alliance and a strategic vacuum that Moscow could exploit.

Watch For

Concrete U.S. policy shifts such as troop withdrawals from Europe, changes to NATO command structures, or formal limitations on Article 5 commitments; the next NATO summits and defense ministerial meetings where U.S. declaratory policy may be clarified; European announcements of increased defense spending and joint procurement; any Russian probing actions along the Baltic or Polish borders designed to gauge allied resolve.