That's the question raised by Bill Kristol in a Weekly Standard article:

...seventy years ago——Hitler's Germany occupied the Rhineland. The French prime minister, Léon Blum, denounced this as "unacceptable." And did nothing. As did the British. And the United States.

In a talk last year, Christopher Caldwell quoted the great Raymond Aron's verdict: "To say that something is unacceptable was to say that one accepted it." Aron further remarked that Blum had in fact seemed proud of France's putting up no resistance. Indeed, Blum had said, "No one suggested using military force. That is a sign of humanity's moral progress." Aron remarked: "This moral progress meant the end of the French system of alliances, and almost certain war."

Today, it is President Bush who has said (repeatedly) that Iran's "development of a nuclear weapon is unacceptable, and a process which would enable Iran to develop a nuclear weapon is unacceptable." The "reason it's unacceptable," the president has explained, is that "Iran armed with a nuclear weapon poses a grave threat to the security of the world." The Iranians must "not have a nuclear weapon in which to blackmail and/or threaten the world."

Is the America of 2006 more willing to thwart the unacceptable than the France of 1936? So far, not evidently. According to the New York Times, "One of President Bush's most senior foreign policy advisers" recently told a group of academics, "The problem is that our policy has been all carrots and no sticks. And the Iranians know it."

Ed Lasky  4 13 06