The present Washington parlor game is to argue over the consequences of a precipitous withdrawal from Iraq. Vietnam is often the referent for both sides — the Left claiming that at least American human and material costs ceased after 1975, as Vietnam eventually found a weary sort of equilibrium. The Right replies with the genocide in Cambodia, the Boat People, and the thousands of Vietnamese executed and sent to reeducation camps — and, of course, the three decades of tyranny that followed.

But even that notorious parallel is inexact. Almost all American ground troops were already gone from Vietnam by 1973, in Richard Nixon’s multi-year “Vietnamization” plan of withdrawal that had slowly reduced our footprint from over a half-million soldiers to about fifty. That surreal scene of American choppers on the Saigon-embassy roof in 1975 was an evacuation of diplomatic personnel and loyal South Vietnamese desperate to flee Communism, not a mass flight of American military personnel in the face of battle.

In fact, the military of the United States has never abandoned an entire theater of operations in its history. It lost its army in the Philippines in 1942, but did not flee. The disasters in Mogadishu and Beirut — as hallowed to the architects of radical Islam as the bloody victories of Iwo Jima and Okinawa are to us — were small affairs involving minimal numbers of ‘peace-keepers.” Wake Island and the Kasserine Pass are still infamous six decades after the fact, but both were tactical defeats under fire, not wholesale theater abandonments of the battlefield.

In truth, this country has never quite experienced anything like the French collapse in 1940 or its precipitous withdrawal from Algeria in 1962, or the implosion of Soviet forces in Afghanistan and Eastern Europe in the late 1980s, much less the more rapid backpedaling of entire German army groups in 1944 on both the Western and Eastern fronts.

What would be the consequences of such a novel experience? Who knows? But the Left is probably correct — cf. the July 8 editorial in the New York Times — that we could probably redeploy without significant casualties. And it is likewise prescient to anticipate that mass killings in Iraq would probably follow — if not a Cambodia-like holocaust, at least something akin to the gruesome fate of the Harkis, those Algerians loyal to France, but left behind to be disemboweled after the French flight across the Mediterranean.

It is easier to envision post-democratic Iraq as a tripartite badlands: a shaky Kurdistan living under the fear of alternate invasion from either oil-hungry Turkey or an ascendant Iran; a Sunni Anbar serving, like Waziristan or Somalia, as a terrorist haven, effused with Wahhabi money and sharia courts; and an Arab Shiite rump state of Iran, residing in safety under an Iranian nuclear umbrella, that would be the convenient jumping off point for Shiite insurgents in the Gulf States. The sorting out of populations into these various enclaves would be messy and bloody, if not like the Pakistani partition of 1947, at least akin to what we saw in the Balkans during the 1990s.

What would the effect be of all this televised carnage and chaos on the United States? Antiwar critics would turn on a dime — disclaiming their prior assertions that our presence ipso facto had been the chief cause of the violence in Iraq. Instead, when the mass beheadings of female reformers and serial shootings of “collaborators” appeared on our screens, American and European leftists would almost immediately blame our fickleness for the carnage. Theirs would not be entirely a humanitarian critique — that our withdrawal was not handled sensibly or with proper concern for civilian security — as much as a damning indictment of our military incompetence, far greater than the 1990s furor during the no-fly-zone years over the Shiite and Kurdish massacres that resulted from our failure to go to Baghdad in 1991. Just as our resolve and stubbornness are now alleged to have resulted in the deaths of thousands, so our irresoluteness would soon be cited for the murders of tens of thousands.

A second effect would be a sort of psychological devastation of the U.S. military, particularly the army. Critics of the Iraq war allege that once out of Iraq, we would not have precious assets exposed in Iraq (where the enemy is), and thus enjoy better options in dealing with, for example, Iran. But what precisely is the point? That our military would flee the messy encounter with al Qaeda to reengage al Qaeda on supposedly better terrain and with better odds? As in Afghanistan? The Pakistani borderlands? Or that a Shiite Iran should be fearful of an America freed up through defeat by Sunni terrorists?

Why would an Islamist cadre bumble into a clean-shooting war with our superior ships and planes when it had previously mastered the blueprint of fighting our foot soldiers house-to-house? If we take out nuclear installations in Iran cleanly from the air, we forget that the retaliation will not be with Scud missiles, but more likely terrorist attacks against our troops somewhere in the Middle East or our civilians at home — as all such deterrence against such terrorism will be lost in the mess in Anbar.

So we forget that armies are living, breathing organisms in which, as Napoleon warned, the moral is to the physical as three is to one. In other words, an exhausted American public and a defeated U.S. military would not for some time be either willing or capable to face another enemy — any more than France after 1962 could be a reliable NATO ally, or Argentina was a renewed threat to the Falklands in 1985, or Britain after Suez could play a prominent role in the Middle East.

Militaries that are beaten and flee take decades to reconstitute and regroup. Command, the mood of the rank-and-file, an army’s self perception — all that is recast in the shadow of recrimination, no more capable of quick resurgence than a boxer recapturing the championship after a surprised, terrible beating.

Indeed, even after the five-year withdrawal from Vietnam, the American military took twenty years to regain its own confidence. If we blame a Jimmy Carter for the Iranian hostage crisis, the Soviet invasion of Afghanistan, the unchecked Cambodian genocide during 1977-79, or the communist infiltration of Central America, he can at least claim he was a mere epiphenomenon of the times — that a war-weary American public and a demoralized military were in no shape to engage in another disastrous foreign adventure.

One of the most surreal sound-bites of the First Gulf War was President Bush’s assertion that the “ghosts of Vietnam have been laid to rest” — this a half-world away, and some 18 years after the last combat troops had left South Vietnam! And if we worry that our new president in 2008 will have to worry about thousands of soldiers still in Iraq, we should worry even more that he will immediately be challenged by all sorts of enemies emboldened by the nature of our flight from Iraq.

In fact, “redeployment” is a euphemism for flight from the battlefield. And we should no more expect an al Qaeda that won in Iraq to stop from pressing on to Kuwait or Saudi Arabia than we should imagine that a defeated U.S. military could rally and hold the line in the Gulf. Would the IEDs, the suicide bombers, the Internet videos of beheadings, the explosions in schools and mosques cease because they now would have to relocate across the border into Kuwait or Saudi Arabia?

In essence, the American military would be reconstituted for a generation — and recognized as such by our enemies — as a two-pronged force of air and sea power. The army at best would stay capable of fighting non-existent conventional wars but acknowledged as incapable of putting down increasingly frequent insurgencies. If Vietnam, Beirut, or Mogadishu left doubt as to the seriousness of American guarantees, Iraq would confirm that it is a dangerous thing to ally oneself with an American government and military. Aside from realignment in the Middle East, South Korea, Taiwan, and the Philippines would have to make the necessary “readjustments.”

The “surge” would be our high-water mark, a sort of 21st-century Pickett’s charge, after which skilled retreat, consolidation, holding the line, and redeployment would be the accepted mission of American arms.

It is not easy securing Iraq, but if we decide to quit and “redeploy,” Americans should at least accept that the effort to stabilize Iraq was a crushing military defeat, that our generation established a precedent of withdrawing an entire army group from combat operations on the battlefield, and that the consequences will be better known even to our enemies than they are to us.

©2007 Victor Davis Hanson