Opinion | Biden’s Red-Line Moment With Iran

Secretary of State Antony Blinken warned Tuesday that the U.S. would respond “swiftly and decisively” to any attack on American forces from Iran or its proxies. That’s a welcome message aimed at deterring the mullahs in Tehran and their agents. But will the President enforce the red line he appears to be drawing? He hasn’t so far.

“The United States does not seek conflict with Iran,” Mr. Blinken said at the United Nations. “We do not want this war to widen. But if Iran or its proxies attack U.S. personnel anywhere, make no mistake. We will defend our people.” Mr. Blinken’s remarks are the sharpest U.S. warning to Iran so far, and from the most senior U.S. official. They go beyond President Biden’s previous vague warnings of “don’t” to discourage Hezbollah or Iran from getting involved in the Hamas-Israel war.