The most consequential NATO summit in years opened in Ankara on Tuesday, with Donald Trump arriving having already made his position clear: European allies must stop writing cheques and start fielding weapons. All 32 member-state leaders are present, joined by two non-member heads of state — Ukraine's Volodymyr Zelenskyy and South Korea's Lee Jae-myung. Defence ministers from Australia, Japan, New Zealand, and four Gulf states — Bahrain, Kuwait, Qatar, and the UAE — are also in the room, a sign that the alliance's concerns now extend well beyond the North Atlantic. The spending debate has already produced a headline number.

At last year's summit in The Hague, members agreed to push their collective target to five percent of GDP: 3.5 percent earmarked for direct military expenditure by 2035, and a further 1.5 percent for broader security needs. That is a sharp climb from the two-percent benchmark that, during Trump's first term, only five countries were actually meeting.

The pressure Trump applied then helped move the needle; the question now is whether money on paper will translate into tanks, missiles, and trained personnel in the field. Experts are divided on that point. Ozgur Unluhisarcikli of the German Marshall Fund argues the Ankara talks are substantively stronger than The Hague round, because the agenda has shifted from pledging funds to building real capabilities.