The Obama administration has reportedly opened a "secret" line of communication between Washington and Tehran in order to warn leaders there that closing the Strait of Hormuz would provoke an American response. According to The New York Times, the no-longer-secret secret messages have been relayed directly to Ayatollah Ali Khamenei to emphasize how seriously the Americans are taking this situation.

Some administration officials have already stated publicly that closing the Strait — and blocking the millions of gallons of oil that move through it every day — is a "red line" that should not be crossed and that the United States would take military action to re-open it. However, the White House apparently felt the need to stress the matter directly to Iran's top leaders, and not through the usual diplomatic channels. The United States and Iran do not have formal diplomatic relations, but usually rely on the Swiss embassies to conduct any necessary business. According to The Times, Switzerland was not involved in these latest messages about the Strait of Hormuz.

While American military officials say they aren't concerned about their ability to re-open the Strait, they are worried that a rogue Iranian naval captain is all it would take to spark a major international incident.