It was no certainty that John Kerry and his colleagues from other countries would be able to conclude their recent deal with Iran. But what was absolutely certain was what would come next: Immediate shouts of “Munich.”

Needless to say, Benjamin Netanyahu—who keeps a portrait of Sir Winston Churchill in his office, and for whom every month is September 1938—has cried betrayal: Barack Obama is the new Neville Chamberlain, and the Iran agreement is a new Munich. The refrain quickly sounded on Capitol Hill. For one example among many, Rep. John Culberson (R-Tex) tweeted “Worse than Munich,” along with a link to a Breitbart News item that juxtaposed Kerry and his Iranian counterpart with Hitler and Chamberlain, respectively. Allen West is no longer a Florida congressman, but he remembered to chime in: “America just had a modern-day Neville Chamberlain moment.”

Mind you, sympathy for Kerry should be qualified. In Paris in early September—speaking in the accurate French for which the Republicans once derided him— Kerry tried to persuade a skeptical French public about the need to intervene in Syria: “This is our Munich moment ... our chance to join together and pursue accountability over appeasement.”

But then when is it not a Munich moment? “I think that no episode, perhaps, in modern history has been more misleading than that of the Munich conference,” George Kennan told the Senate in 1965. By that point, words “Munich,” “appeasement,” and “Chamberlain,” had not been merely misunderstood, as Kennan said, but repeatedly misprized and misapplied, very often with disastrous consequences. A complete list would fill a book, but here are a few items.

When Communist forces invaded South Korea in 1950, President Harry Truman invoked the spectre of Munich as the United States went to war: There must be no appeasement this time. After the initial American disasters, General Douglas MacArthur landed behind enemy lines at Inchon and drove the invading forces deep into North Korea. As he approached the border with China on the Yalu River he was warned that any further advance might provoke Chinese intervention; MacArthur replied that to halt would be to appease the Chinese, as the British had appeased Hitler. He duly advanced to the Yalu, whereupon a vast Chinese army fell on his forces and drove them all the way back again.