The triumphs and question marks from this week’s NATO summit

This summer blockbuster lived up to the hype. In Madrid this week, NATO allies substantially boosted their forces in Eastern Europe, struck a deal to invite Sweden and Finland into the club, and dropped a once-in-a-decade strategic concept that strove to break new ground on China and climate change. What do these developments mean—and which ones flew under the radar? How will history judge this consequential gathering? From Madrid to Washington, our experts are here with answers.