US Secretary of State Antony Blinken has made a surprising revelation: for the past 20 years, the United States has tried—and failed—to change the government in Iran. Speaking at a public event in New York on Wednesday, Blinken openly admitted that these attempts at regime change have not been successful, despite years of effort.

The admission came when Blinken was asked if the US should continue trying to remove the current leadership in Iran. With a laugh, he confessed that the US’s ef...