As in most crises, so, too, in the case of Iraq, analogies to the 1930s and Munich are being drawn. Saddam is Hitler, the French and Germans the appeasers, Bush is Churchill. Fox News’ Brit Hume has dubbed French Foreign Minister De Villepin a Vichyite.

President Bush, too, sees close comparisons, warning that if the UN does not show more “backbone,” it risks going the way of the League of Nations, ending up as an international “debating society.”

But what really happened to the League? Why did it fail?

Created at the Paris Peace Conference, the League’s Covenant was embedded in the text of the Versailles Treaty at the insistence of its great patron Woodrow Wilson. But when the U.S. Senate proposed reservations to the Covenant, to protect U.S. sovereignty and freedom of action, the president rejected them all. The Senate then rejected the treaty, and the United States never joined the League.

Its first crisis came in 1931. Japan had watched with rising alarm a civil war in China between the Communist armies of Mao Tse-tung and the Nationalists of Chiang Kai-shek. With Stalin aiding Mao and encroaching in Mongolia and North China, Japan decided to move its army deep into Manchuria and establish a buffer state it called Manchukuo.

After an investigation and report, the League found Japan guilty of aggression. But its only two members with the power to intervene, Britain and France, had no interest in confronting Japan over North China. Nor did the United States. So, Tokyo was verbally thrashed. But, humiliated and enraged at the insult, the proud Japanese walked out of the League.

A second blow to the League came in 1933 when Hitler, having won power on a platform to restore German rights and lands taken away at Versailles, also walked out of the League, which had been established in part to enforce the terms of Versailles.

A third crisis came in 1935 when Mussolini, after a border incident between Italian Eritrea and Ethiopia, ordered his army to invade. Italy overran Ethiopia, whose emperor, Haile Selassie, made a dramatic personal appeal to the League.

The British public was in favor of League action, but British interests dictated against. Italy was a long-time friend. Mussolini had stood up to Hitler at the time of the attempted Nazi coup in Vienna in 1934 and had invited Britain and France to join his Stresa Front against the Reich.

Moreover, the British and French empires had dozens of African colonies. To confront Italy militarily over a land-locked colony in the heart of the continent seemed not to be worth it. Their real concern was Germany, not Italy.

Still, public pressure forced Britain and France to impose sanctions on Italy, though these did not include an embargo of oil, the one import that was critical to Mussolini. Italy’s prime supplier of oil, the United States, declined to join in the sanctions, thereby eviscerating them. FDR had no wish to antagonize millions of Italian-Americans expected to go to the polls in November 1936.

When Hitler, in flagrant violation of Versailles, moved troops into the Rhineland in March 1936, the League talked but failed to act. Nor was anything done to block his Anschluss with Austria in 1938, or annexation of the Sudetenland after Munich, or to interfere with the Nazi protectorate Hitler assumed over the remnant of the Czech state in 1939.

The League was finished. But in the final analysis, it was not the League that failed. It was the Allies that failed. Neither Britain nor France—nor the United States—was willing to risk war for high principle, if validating that principle imperiled vital interests.

None of the three had a vital interest in whether or not Japan (or Russia or China) controlled Manchuria. And if the United States refused to join the League, how could nations object if Germany walked out?

As for Ethiopia, was upholding the principle of non-aggression in Africa worth a war that might drive Italy into the arms of Nazi Germany? Indeed, the limited sanctions imposed on Italy helped to create the Rome-Berlin Pact of Steel, that first Axis of Evil.

As for Hitler’s military occupation of the Rhineland, this was a direct challenge to France. But if France, with its huge army, would not act militarily in its own vital interests, why should anyone else?

The lesson seemed clear then and does today. Great nations will not allow the claims or commands of multinational institutions to take precedence over vital interests. The crucial choice—of non-intervention, sanctions, or war—will ultimately be dictated by national interests alone.

Mr. Bush is doing the same thing, only he believes war is the right course. And whether the UN agrees or not is, in his word, “irrelevant.”