On Saturday, the Ukrainians hit the Kerch Strait Bridge, which leads from Russia to Crimea, with something—a missile, explosives planted by naval commandos, a truck laden with explosives. No one who knows is saying for sure.(snip)The tactical questions of how the Ukrainians pulled off this strike and of whether lasting damage has occurred are interesting and important but currently unresolvable publicly. What can, however, be more profitably discussed is what this tells us about where the Russia-Ukraine war is headed. “Battles are the principal milestones of secular history,” Winston Churchill wrote in his biography of the Duke of Marlborough. The...