US formally reevaluates NATO membership as allied airspace denials mount

The Trump administration is formally reevaluating US membership in NATO, according to Ambassador Matthew Whitaker, following a series of European airspace denials that have blocked American military operations related to the Iran conflict. The convergence of official US skepticism and allied operational restrictions represents the most serious structural challenge to the 73-year-old alliance since its founding.

Whitaker’s April 1 statement to Newsmax marks the first time a senior administration official has confirmed a formal policy review of NATO membership. The assessment follows Austria’s rejection of “several” US requests to use its airspace for military operations related to the Iran War, citing its constitutional neutrality law. Spain expanded its ban on US military flights this week, with Foreign Minister José Manuel Albares telling Rac 1 Radio that “Spain should not do anything that could escalate” the conflict. Italy previously denied a US aircraft permission to land while en route to a Middle East combat mission.

allied cohesion fractures independent of US posture

The pattern of denials suggests cracks in allied cohesion that predate Trump’s current reconsideration. Austria’s neutrality policy has been in place since 1955, but the Defense Ministry’s explicit rejection of requests tied to the Iran conflict—launched February 28 by the US and Israel—marks the first time Vienna has publicly blocked American operations during an active theatre engagement involving a NATO member. Spain’s restriction reflects what Albares described as the “majority sentiment” of Spaniards opposing the war, aligning with UN principles rather than alliance obligations.

Secretary of State Rubio told Fox News on April 1 that the administration will “have to re-examine whether or not this alliance that has served this country well for a while is still serving that purpose, or is it now become a one-way street where America is simply in a position to defend Europe, but when we need the help of our allies, they’re going to deny us basing rights and they’re going to deny us overflight.” The framing positions allied restrictions as breach of reciprocal defense obligations, though none of the denying nations are obligated under Article 5 to support non-defensive US operations outside NATO territory.

defense spending accelerates as alliance wobbles

European NATO members have entered a decisive acceleration phase independent of the current crisis. At the June 2025 Hague summit, allies committed to 5 percent of GDP on defense by 2035, with a 3.5 percent core benchmark. Germany’s defense budget rose 23 percent in real terms in 2024 and 18 percent in 2025, reaching €95 billion—double its 2021 level—with projections of €162 billion by 2029 (3.5 percent of GDP), according to the European Parliament.

Global defense spending is expected to hit $2.6 trillion in 2026, an 8.1 percent increase over 2025, and reach $2.9 trillion by decade’s end, according to Forecast International. The S&P Aerospace and Defense Select index climbed 11 percent year-to-date through early February, driven by geopolitical uncertainty and elevated procurement expectations. The State Street SPDR S&P Aerospace & Defense ETF (XAR) returned 10.5 percent versus 1 percent for the S&P 500 over the same period.

contractor backlogs signal multi-year visibility

Defense contractors have secured order books extending through 2028. Lockheed Martin holds a $179 billion backlog while RTX’s order book stands at $251 billion, providing exceptional revenue visibility regardless of near-term alliance turbulence. The figures reflect procurement commitments made before the current NATO crisis, suggesting European spending acceleration would continue even if the US formally withdraws.

The contradiction is structural: European allies are increasing defense budgets in response to perceived threats from Russia and instability in the Middle East, yet several are simultaneously restricting US operational access based on neutrality principles or domestic political opposition to specific conflicts. This divergence—higher spending, lower operational alignment—undermines the alliance’s functional premise even as formal commitments expand.

geopolitical realignment accelerates

Trump told The Telegraph on April 1 that his reconsideration goes “beyond” mere review: “I was never swayed by NATO. I always knew they were a paper tiger, and Putin knows that too, by the way.” The framing positions US withdrawal as validation of pre-existing alliance dysfunction rather than rupture. Russia and China stand to benefit from any formal US decoupling, with Moscow gaining tactical leverage in Ukraine negotiations and Beijing facing reduced coordination among Pacific allies who rely on NATO interoperability frameworks.

NATO Secretary General Mark Rutte will travel to Washington next week for a “long-planned visit” and is scheduled to meet with Trump, according to Time. The session will be the first direct engagement between alliance leadership and the White House since Whitaker’s reevaluation statement.

what to watch

Rutte’s Washington visit (week of April 7) will clarify whether the administration’s review is tactical leverage or structural policy. Watch for any joint statement language on burden-sharing or operational reciprocity—absence of such language would signal deepening divergence. Monitor whether additional European members expand airspace or basing restrictions, particularly Poland and the Baltics, whose security posture depends entirely on US commitment. Defense contractor earnings calls in late April will reveal whether procurement timelines have accelerated in response to alliance uncertainty. Finally, track whether Russia or China make formal diplomatic overtures to European capitals, testing alliance cohesion through economic or security inducements. The next 30 days will determine whether NATO’s crisis is negotiable or terminal.