For the United States, the Iraq war ranks as the most consequential foreign policy failure since Vietnam. In neither instance did U.S. forces succumb to outright defeat, of course. In both, with victory proving elusive, Americans wearied of the fight and simply walked away, abandoning the people for whom their troops had ostensibly fought.
In terms of outcomes, however, these two conflicts differ in crucial respects. In Vietnam, we quit and got away with it. Lyndon Johnson's recklessness in expanding the war found its counterpart in Richard Nixon's cynicism in ending it. When after a mere three years of "peace with honor" the Republic of Vietnam collapsed, Americans shrugged.
In Southeast Asia, many people - Vietnamese, Cambodians, Laotians - paid (and continue to pay) for the havoc that the United States wreaked there. By comparison, even taking into account the 58,000 American dead, this country paid next to nothing.
Strategically, the United States got off scot-free. Committing to memory the war's canonical lesson - "No more Vietnams" - Americans moved on. That was that.
Iraq offers a striking contrast. Considerably smaller in scale than Vietnam, America's misadventure in Iraq has already given rise to vastly larger strategic implications. There, recklessness has found its counterpart not in cynicism but in an unfathomable combination of naivete and listlessness. The recklessness was that of George W. Bush. The naivete and listlessness - grandiose talk seldom translating into concerted action - have become the hallmarks of Barack Obama's approach to statecraft.
Today, less than three years after President Obama declared that the Iraq war had ended - "an extraordinary achievement, nearly nine years in the making" - Iraqis confront the fate that befell the South Vietnamese. From the north, enemy formations - in 1975, it was the People's Army of Vietnam; today, the legions of the Islamic State of Iraq and Syria, or ISIS - are on the march. For observers of a certain age, the mournful roll call of fallen cities recalls the events of that earlier debacle.
Then, it was Ban Me Thuot, Kontum and Pleiku. Today, it's Mosul and Tikrit, with Samarra hanging in the balance. Then, the ultimate objective was Saigon. Today, Baghdad.
Baghdad itself may or may not eventually fall. Even so, the ISIS offensive has demolished the pretense that America's war in Iraq ended in something akin to success, thanks ostensibly to David H. Petraeus and his "surge." For Iraqis, their decent interval has expired and their day of reckoning is at hand. This time, however, in contrast to Vietnam, circumstances will not permit Americans to shrug off the aftermath.
Undertaken as a campaign in the Cold War, the Vietnam War proved irrelevant to the Cold War's eventual outcome. Undertaken as a campaign in the misnamed global war on terrorism, the Iraq war has proved anything but irrelevant. Instead, it has destabilized much of the greater Middle East while exacerbating anti-Americanism across the Islamic world.
To extricate the United States from the unpopular war he had inherited from his predecessor, President Nixon sold out the South Vietnamese. Yet by simultaneously reaching an accommodation with China, he managed at least one trick: By the time Saigon fell, Nixon had reduced by one the roster of countries that Washington counted as problems or threats. He thereby salvaged a modicum of advantage acutely relevant to the as-yet-undecided Cold War.
Obama is not guilty of consciously selling out a former ally. To extricate the United States from an equally unpopular war that he inherited from his predecessor, he merely cut Iraq loose. Perhaps he had little alternative but to do so. Yet in terms of implications, Obama's actions are much the same as Nixon's: Iraqi problems are no longer our problems.
Unfortunately, signs of Obama repeating Nixon's trick - offsetting failure in Iraq by securing compensatory advantage elsewhere - are hard to find. Instead, the roster of countries across the Islamic world that Washington views as problems or threats has grown appreciably.
As shrewd as he was amoral, Nixon contrived a way to limit the damage that Vietnam had done to U.S. interests. Obama has yet to demonstrate any comparable ability to limit the damage done by the Iraq war.
One glimmer of opportunity remains, in terms of daring and audacity the closest thing to a Nixonian gambit: Ending the U. S. diplomatic estrangement from Iran could yield a strategic realignment comparable to that produced by the opening to China, its effects rippling across the greater Middle East. There, rather than in misguided proposals for renewed U.S. military action, lies Obama's chance to demonstrate that he has grasped the lessons that Iraq (along with Vietnam) has to teach. One can imagine Nixon himself relishing the prospect.
Andrew J. Bacevich is a professor of history and international relations at Boston University.