Mihail Kogalniceanu Air Base in Romania, long a symbol of American military presence in Europe, exemplifies the complex state of the North Atlantic Treaty Organization (NATO) under the Trump administration’s pressure campaign. Since 1999, the base, named after American states and figures such as Alabama and George Washington, has hosted U.S. forces supporting operations in Iraq and Afghanistan. However, beginning last year, roughly half of the 2,000 U.S. troops stationed there departed amid President Donald Trump’s efforts to realign American military commitments in Europe.

Romania, a NATO member bordering Ukraine, views the base as a critical outpost on the alliance’s eastern flank, especially as Russian drone activity has sporadically crossed into NATO airspace. Despite initial troop withdrawals, key American military assets such as nine KC-135 Stratotanker refueling aircraft remain stationed at the base, underscoring continued U.S. reliance on European infrastructure to project power both in Europe and the Middle East.

Trump’s approach to NATO has been marked by demands for increased defense spending among allies, threats of troop cuts, and criticism of European governments for not fully backing the U.S.-led campaign against Iran. Yet, behind the rhetoric, U.S. investment in major European military facilities continues, reflecting Washington’s enduring strategic interests on the continent.

Interviews with more than 50 officials—including military personnel, diplomats, and former administrators—highlight an alliance under strain but not fractured. Congressional lawmakers from both parties, alongside defense contractors with significant European markets, hold the political influence to prevent a full U.S. withdrawal from NATO, despite Trump’s repeated threats. Nonetheless, a loss of transatlantic trust is palpable, affecting defense planning and procurement decisions among member states.

Many European countries are increasing defense budgets, motivated as much by Russia’s 2022 invasion of Ukraine as by U.S. pressure. However, several, including Canada, Poland, Denmark, and Spain, are beginning to diversify away from U.S. weapons systems and technology—potentially complicating future U.S.-European military interoperability. Some defense analysts warn this shift may undermine the American defense industrial base and the coherence of NATO’s collective deterrence.

The Pentagon’s ongoing review of U.S. force posture in Europe, initially intended to announce a potential reduction of 25,000 troops, illustrates internal debates over balancing America’s desire to "Europeanize" defense with maintaining influence and readiness. Resistance within the U.S. administration and Congress has delayed formal troop cuts, with officials emphasizing the seriousness and consultative nature of the review. The U.S. currently maintains over 81,000 military personnel in Europe, a number that fluctuates with deployments and exercises.

At the NATO summit in Ankara in July 2025, Trump credited himself with prompting a $150 billion increase in European defense spending but also publicly critiqued allies such as Spain and Italy over logistical support and policy disagreements. European leaders, including Spain’s Prime Minister Pedro Sanchez, emphasized sovereign decisions regarding American deployments, underscoring ongoing cooperation despite tensions.

Amid these dynamics, Russia has intensified provocations along NATO’s eastern border, including drone incursions and missile strikes targeting NATO territory in Romania and Poland. NATO member countries attribute these actions to Moscow’s strategy to weaken alliance cohesion. Russia denies involvement, framing such incidents as provocations.

Meanwhile, several NATO countries are reassessing defense procurement policies. Canada’s recent purchases of Arctic radar systems and early-warning aircraft from non-U.S. suppliers have drawn scrutiny from Pentagon officials concerned about alliance unity. European nations increasingly view deep dependence on U.S. military technology and political leadership as a strategic risk, spurring efforts to enhance defense autonomy.

Despite persistent public affirmations of transatlantic solidarity, private concerns linger among U.S. and European officials about America’s long-term commitment. Opinion surveys reveal diminished European confidence that the U.S. would honor collective defense commitments, a situation exacerbated by Trump’s divisive stance toward the alliance.

The current phase of NATO’s evolution reflects broader shifts in U.S. foreign policy towards a more transactional and unilateral approach under Trump’s “America First” doctrine, challenging the post-World War II multinational security order that has underpinned European stability for more than seven decades. How the alliance adapts to this transformation, while countering Russian aggression, remains a critical question for European and American defense planning moving forward.