Less than a week before NATO leaders convene in Ankara, President Donald Trump has declared it “ridiculous” for the United States to maintain its current level of support for the alliance, writing on his Truth Social platform that Washington’s relationship with NATO “is not reciprocal” and that European allies “were not there for us.” The statement, issued as Trump prepares to travel to the Turkish capital for a bilateral meeting with President Recep Tayyip Erdoğan on the eve of the 7–8 July summit, crystallises a dispute over burden-sharing that has been sharpened by the war in Iran. Several European governments restricted access to bases for US forces during that conflict, a move that, viewed from Washington, confirmed a long-standing complaint that allies are unwilling to share the military and political costs of collective defence.

According to US officials, the administration intends to use the Ankara gathering to enforce spending commitments agreed at the previous summit in The Hague, where allies pledged to allocate at least 5 percent of GDP to security by 2035, with 3.5 percent directed to strictly military expenditure. Defence Secretary Pete Hegseth has warned that if targets are not met, the American contribution to NATO’s common budget will decrease, describing the alliance as “a two-way street.” The Pentagon is already conducting a six-month review aimed at reducing the US military footprint in Europe, including the possible withdrawal of one of two carrier strike groups and all American submarines assigned to the alliance. Secretary of State Marco Rubio has called the Ankara meeting “probably the most important in the organisation’s history,” a characterisation that European diplomats do not dispute.

From London, Paris and Berlin, the response has been a scramble to demonstrate both fiscal resolve and strategic autonomy. British Prime Minister Keir Starmer announced a £15 billion military investment plan this week, though it contains a £4.7 billion funding gap that will fall to his likely successor, Andy Burnham, to address. Major European powers held preparatory talks before the summit in an effort to arrive in Ankara with a common position on Ukraine, whose eventual NATO membership remains a formal promise without a timeline. Yet European officials acknowledge that decades of dependence on American defence capabilities cannot be unwound in one or two budget cycles, and that building an independent industrial base and operational doctrine will require sustained political will that is far from guaranteed.

The summit unfolds against a backdrop of multiple, overlapping security crises. NATO Secretary General Mark Rutte has assessed that Russia could be ready to use military force against the alliance within five years, making the posture on the eastern flank a central negotiating item. The war in Iran, despite a memorandum of understanding signed by Trump and Tehran on 18 June, continues to generate friction: Italy’s refusal to permit the refuelling of US aircraft in Sicily during bombing operations led to a public clash at the G7, and the encounter between Trump and Prime Minister Giorgia Meloni in Ankara will be among the most closely watched of the summit. A potential bright spot for bilateral ties is the expected US approval of the sale of engines for Turkey’s Kaan fifth-generation fighter, a deal that Ankara views as critical to fielding the aircraft by 2030. The 32 heads of state and government are set to decide on a new burden-sharing framework and a revised US force posture before the summit concludes on 8 July.