Since the completion last year of a landmark deal limiting Iran’s nuclear program, the country’s supreme leader, Ayatollah Ali Khamenei, has lashed out again and again at the U.S. for its supposed failure to live up to its end of the bargain. But a speech he gave on Aug. 1 in Tehran took his anti-American rhetoric to a new level. He accused the Obama administration of a “bullying policy” and of failing to lift sanctions in a way that benefited “the life of the people.” Mr. Khamenei ruled out cooperation with the U.S. in the fight against Islamic State in Iraq and Syria, telling his audience that Iran’s experience with...