At a moment when the world's oil arteries remain perpetually vulnerable, Donald Trump has signaled that a consequential decision on Iran now sits before him, while Iran's Revolutionary Guard has struck a commercial tanker in the Strait of Hormuz — the narrow passage through which a third of the world's seaborne oil flows. These two acts, one rhetorical and one kinetic, have arrived together in a region where the distance between warning and war has always been dangerously short. History will record whether this week marked the beginning of a confrontation or merely its loudest rehearsal.