Less than two weeks before a NATO summit, Sweden and the Netherlands said Friday that they intend to increase defense spending to 5% of their gross domestic product, in line with U.S.

Anticipating a world in which the United States no longer contributes to Europe’s defense, Sweden is about to spend more money on its military—and on the Ukrainian military. A lot more.

Vladimir Medinsky warned, in an interview, that Ukraine would lose more territory if it doesn’t agree to Moscow’s imposing ...