DUBAI, Aug. 24 -- For the tanker crews navigating the Persian Gulf with their automatic identification systems disabled, Monday's declaration from Tehran arrived as confirmation of what the shipping lanes had been signaling for months: the rules governing this waterway are being written in Tehran, not Washington.

Mohsen Rezaei, head of Iran's Supreme National Security Council, issued the warning with characteristic directness. "If the countries surrounding Iran join the Americans in the economic war, not a single drop of oil will leave the Persian Gulf and the Strait of Hormuz," he said, according to RT.

The statement arrived as the 60-day negotiation window that US President Trump had granted Iran to reach a new nuclear and regional se...