WASHINGTON, June 9 -- The explosions in Haifa and the petrochemical fires along the Iranian coast have commanded most of the attention. What has not is the thing Donald Trump keeps returning to, with unmistakable satisfaction, every time a reporter asks whether the deal is dead: the blockade.

"The blockade that we have, the naval blockade is incredible," Trump told reporters at the Oval Office last week, in remarks reported by CNN. "Not one ship has gotten through unless we wanted it to, and people respect it a lot." He was not talking about bombs or missiles or the hundred days of air strikes that have hollowed out Iranian air defenses. He was talking about commerce. About the slow suffocation of an economy through sealed sea lanes.

Th...