In a stunning sequence of events, the Russian military opened fire then seized three Ukrainian navy vessels in an unprovoked attack on the Black Sea last Sunday. In the melee, several Ukrainian sailors were wounded and 24 captured. Moscow followed up this flagrant act of war by parading the sailors on Russian television to give clearly coerced confessions of guilt. This attack is but the latest escalation in the ongoing Russian war against Ukraine that has been churning since 2014. It’s also the first great test for the Trump administration regarding Russia and one that will have lasting consequences on...