Who’ll blink first? The New York Times reports that using secret communications, the Obama administration has directly warned Iran’s Supreme Leader that blocking the Strait of Hormuz is a “red line”—and the United States will take action. Iran has threatened to block the strait between the Persian Gulf and the Gulf of Oman, which transfers a fifth of the world’s oil everyday. Closing the strait would be “economic suicide” for the nation. The message to Ayatollah Ali Khamenei suggests that the U.S. would consider using minesweepers, warships, or even airstrikes on Iran to free up the strait. The news comes as Iran has said it wants open to “serious talks” with world leaders about its highly secretive nuclear program.