If our wars in the Greater Middle East ever end, it's a pretty safe bet that they will end badly -- and it won't be the first time. The "fall of Saigon" in 1975 was the quintessential bitter end to a war. Oddly enough, however, we've since found ways to reimagine that denouement which miraculously transformed a failed and brutal war of American aggression into a tragic humanitarian rescue mission. Our most popular Vietnam end-stories bury the long, ghastly history that preceded the "fall," while managing to absolve us of our primary responsibility for creating the disaster. Think of them as silver-lining tributes to good intentions and last-ditch heroism that may come in handy in the years ahead.

The trick, it turned out, was to separate the final act from the rest of the play. To be sure, the ending in Vietnam was not a happy one, at least not for many Americans and their South Vietnamese allies. This week we mark the 40th anniversary of those final days of the war. We will once again surely see the searing images of terrified refugees, desperate evacuations, and final defeat. But even that grim tale offers a lesson to those who will someday memorialize our present round of disastrous wars: toss out the historical background and you can recast any U.S. mission as a flawed but honorable, if not noble, effort by good-guy rescuers to save innocents from the rampaging forces of aggression. In the Vietnamese case, of course, the rescue was so incomplete and the defeat so total that many Americans concluded their country had "abandoned" its cause and "betrayed" its allies. By focusing on the gloomy conclusion, however, you could at least stop dwelling on the far more incriminating tale of the war's origins and expansion, and the ruthless way the U.S. waged it.

Here's another way to feel better about America's role in starting and fighting bad wars: make sure U.S. troops leave the stage for a decent interval before the final debacle. That way, in the last act, they can swoop back in with a new and less objectionable mission. Instead of once again waging brutal counterinsurgencies on behalf of despised governments, American troops can concentrate on a humanitarian effort most war-weary citizens and soldiers would welcome: evacuation and escape.

Phony Endings and Actual Ones

An American president announces an honorable end to our longest war. The last U.S. troops are headed for home. Media executives shut down their war zone bureaus. The faraway country where the war took place, once a synonym for slaughter, disappears from TV screens and public consciousness. Attention shifts to home-front scandals and sensations. So it was in the United States in 1973 and 1974, years when most Americans mistakenly believed that the Vietnam War was over.

In many ways, eerily enough, this could be a story from our own time. After all, a few years ago, we had reason to hope that our seemingly endless wars -- this time in distant Iraq and Afghanistan -- were finally over or soon would be. In December 2011, in front of U.S. troops at Fort Bragg, North Carolina, President Obama proclaimed an end to the American war in Iraq. "We're leaving behind a sovereign, stable, and self-reliant Iraq," he said proudly. "This is an extraordinary achievement." In a similar fashion, last December the president announced that in Afghanistan "the longest war in American history is coming to a responsible conclusion."

If only. Instead, warfare, strife, and suffering of every kind continue in both countries, while spreading across ever more of the Greater Middle East. American troops are still dying in Afghanistan and in Iraq the U.S. military is back, once again bombing and advising, this time against the Islamic State (or Daesh), an extremist spin-off from its predecessor al-Qaeda in Iraq, an organization that only came to life well after (and in reaction to) the U.S. invasion and occupation of that country. It now seems likely that the nightmare of war in Iraq and Afghanistan, which began decades ago, will simply drag on with no end in sight.

The Vietnam War, long as it was, did finally come to a decisive conclusion. When Vietnam screamed back into the headlines in early 1975, 14 North Vietnamese divisions were racing toward Saigon, virtually unopposed. Tens of thousands of South Vietnamese troops (shades of the Iraqi army in 2014) were stripping off their military uniforms, abandoning their American equipment, and fleeing. With the massive U.S. military presence gone, what had once been a brutal stalemate was now a rout, stunning evidence that "nation-building" by the U.S. military in South Vietnam had utterly failed (as it would in the twenty-first century in Iraq and Afghanistan).