In the aftermath of World War I, a large crop of anti-war films rose up from the muddied battlefields of Western Europe. The filmmakers behind these projects were caught up in the belated revelation that “war is hell” — so much so, in fact, that they failed to realize that the massive casualties of that war were a repudiation of 19th-century military tactics rather than war itself.

Their films frequently extrapolated the futility of appalling casualties at Verdun and the Somme into a self-righteous and misguided social commentary on the alleged “uselessness” of war in general. This mentality is still with us today, albeit without the artistic polish that characterized earlier anti-war works.

But as filmmakers went after the war, so did politicians. Every victorious power in World War I learned precisely the wrong lessons from it. Placing all their faith in diplomacy, they unsuccessfully attempted to tame international turmoil through the Kellogg-Briand Pact, the Geneva protocols, the Washington Naval Treaty, the League of Nations and other diplomatic initiatives.

Each Allied nation also adopted its own internal policy responses to the war, all of which turned out to be disastrously ill-conceived. The French built the Maginot Line, the British adopted arms control and “peace at any cost” appeasement as their principal instruments of foreign policy and the United States retreated into impotent, demilitarized isolationism.

In contrast, convinced they had lost the war in spite of — and not because of — their tactics, Germany’s general staff spent the inter-war era secretly combining the old imperial army’s infiltration and shock tactics with mechanization and armored warfare doctrine. This resulted in the famous blitzkrieg that would have conquered Europe had it not been for the strategic incompetence of the Nazis, particularly Hitler and Goering.

In the end, only war, not dialogue, was capable of stopping the genocide of Germany’s Jews, among other atrocities. Books and films depicting the human cost of the bombings of Dresden, Hiroshima and Nagasaki or the tragic story of the brave but doomed defenders of Berlin and Iwo Jima present a valuable perspective, but they can also improperly obscure the ultimate righteousness of the Anglo-American war effort.

Likewise in Vietnam, anti-war activists convinced themselves that the heavy casualties suffered by belligerent soldiers and civilians alike made the war itself wrong, when all it really meant was that the wrong tactics were being employed. All that was needed was proper counterinsurgency doctrine. Still, the egregiously incorrect portrayal of the Tet Offensive as an American defeat (when, in fact, it was a disastrous loss for the communists) sealed the fate of the war effort, and with it millions of South Vietnamese civilians who would be murdered in the lethal simulacrum of peace that followed.

It would be a poor reflection on our ability to learn the right lessons from the wars of the 20th century if we were to assert that the loss of precious lives and resources in Iraq renders the war an ignoble enterprise.

At the same time, we must also recognize that merely “supporting the troops” without demanding the best strategy is not enough. Although the war is just, there is always room for improvement in its execution. Americans of all political persuasions ought to focus on critically debating the best path to a free and stable Iraq instead of taking the setbacks of 2006 as proof that the war is immoral and unwinnable.