Doling out tough love to European countries should top Trumps NATO summit agenda

This week’s NATO summit in Ankara arrives at a fraught moment: Even as America and its allies face growing threats from authoritarian powers, differences over Ukraine, Iran, Greenland and US military commitments in Europe have strained transatlantic ties.That gives President Donald Trump and Secretary General Mark Rutte a golden opportunity to put NATO on the right path.Their first order of business must be spurring further European investment in defense.At last year’s summit, allies committed to allocate 5% of GDP to defense and other security-related priorities by 2035 — a historic decision for which Trump deserves much credit.Some countries, such as Poland and the Baltic states, are already there.Germany, the industrial workhorse of Europe, has begun ramping up spending to correct decades of underinvestment, aiming to become the continent’s strongest conventional force next decade.Yet others, like the UK, are moving in the right direction — but much more slowly.In Ankara, Trump should lavish praise upon the high achievers while pushing the laggards to pick up the pace.The trick is to dish out this tough love without undermining the alliance’s credibility.Trump should emphasize that he seeks not to disengage from Europe, but to strengthen NATO through proper burden-sharing.The allies now understand that Washington expects Europe to “take primary responsibility for its own conventional defense,” as the Pentagon’s 2026 National Defense Strategy declared in January.But getting there will require a generational effort.This transition was never going to be easy, but it doesn’t have to be chaotic.Trump and Rutte therefore should publicly commit to develop — and then stick to — a reasonable NATO transition framework.Allies should never be blindsided by US decisions — as they were in May, when the Pentagon suddenly canceled an Armored Brigade Combat Team’s rotational deployment to Poland, sparking widespread concern.That should have been a less...