Security on NATO’s Edge: How Transatlantic Policy Shifts Affect Lithuania

For the past three decades, since the decision to join NATO, the core of Lithuania’s national security outlook has been based on the strategic security partnership with the United States. For Lithuania, the United States has never been just another ally; it has been the ultimate security guarantor without which neither NATO’s Article 5 nor the broader deterrence architecture in the Baltic region (and Europe, in a broader geopolitical picture) would be credible. Lithuanian strategic documents and expert discussions have consistently underlined that U.S. political leadership, military capabilities, and the nuclear umbrella are irreplaceable, particularly given Russia’s aggressive posture and proximity. American troops on NATO’s eastern flank, including in Lithuania itself, directly bind U.S. credibility to Baltic security and dramatically raise the political and military costs for any potential Russian move against Lithuania. In this regard, maintaining the closest possible relationship with the United States for an extended period is not a matter of diplomatic preference but of national survival.

This existential logic has shaped Lithuania’s foreign and security policy since independence. Successive Lithuanian governments have regarded “keeping the Americans in” as a long-term national interest and have actively sought to anchor the United States in Lithuania’s defense, economic, and political ecosystems. Since 2022, Vilnius has consistently exceeded NATO defense-spending benchmarks, moving from above 2% of GDP to a planned 5.38% in 2026, both to strengthen its own defense and to signal to Washington that Lithuania is an ally that “pulls its weight” and more.

The country has welcomed rotational U.S. heavy battalions since 2019, invested heavily in host-nation support infrastructure, and aligned itself closely with U.S. global priorities. From participating in operations in Afghanistan and Iraq to taking a principled stance on China and Taiwan, Lithuania has aimed to stay visible and valuable in Washington. This effort has expanded through extensive connections with the U.S. Congress, the White House, the Pentagon, and the State Department, recognizing that only ongoing engagement with all major branches of American power can secure long-term attention for a small frontline ally.

This strategy has produced tangible achievements, but now Lithuania faces a far more demanding context. Lithuania has benefited from the Baltic Security Initiative (BSI), deeper defense-industrial cooperation, and continuous U.S. rotations in the Baltics and Poland, which together have created an “enduring U.S. footprint” on NATO’s eastern flank. Yet the Trump administration’s second term has already resulted in a partial withdrawal of U.S. troops from Romania and plans to eventually discontinue the Baltic Security Initiative—even though Congress decided to revive it for FY2026. All these signals point to a trajectory of reduced U.S. financial and force commitments in Europe. The new U.S. National Security Strategy 2025 merely confirms these shifting priorities, explicitly indicating that European countries should not only contribute more to NATO defense but also prepare for a significant reduction in U.S. military presence in Europe in the future. Some media sources also highlighted the very short timetable: according to Reuters, the United States wants Europe to take over the majority of NATO’s conventional defense capabilities, from intelligence to missiles, by 2027.

Extensive discussions and foresight workshops with Lithuanian and international experts similarly point to a continued U.S. shift toward the Indo-Pacific, growing protectionism, and an administration that appears “unlikely to extend full security guarantees to Europe.” The National Security Strategy 2025 consolidates this trend by elevating Western Hemisphere and Indo-Pacific priorities and by framing security guarantees for Europe as conditional on the allies’ capacity to assume much greater responsibility for their own defense.

Against this backdrop, the central question for Lithuania remains: how to preserve the U.S. as a security guarantor while realistically preparing for a world in which American engagement in Europe may be limited, more transactional, and more contingent than in the past.