Sometimes the whole country wants to forget.
Tuesday marks the 10th anniversary of the start of the war in Iraq. The last U.S. troops didn't leave that country until the end of 2011.
But Iraq, which dominated much of the nation's political discourse over the past decade, already seems largely forgotten.
"The Iraq War casts a shadow, but not a very large one," says Richard Kohn, a military historian at the University of North Carolina, Chapel Hill.
Iraq still matters in policymaking circles. Its lessons help explain why President Obama waves off calls for a military intervention in Syria.
"There does seem to be an Iraq syndrome, at least in the foreign policy establishment, in showing virtually no commitment for something that might morph into an Iraq or an Afghanistan," says William Wohlforth, a government professor at Dartmouth College.
But Iraq has not led to a wholesale restructuring of the U.S. military, as the Vietnam War did. And as controversial as it was at the time, Iraq did not trigger the sort of political and cultural convulsions that Vietnam did.
Vietnam remained a difficult subject for years, if not decades, after the fighting stopped, while Iraq has already just about disappeared from political discourse.
"When a bad war ends, the inclination is not to think about it and move on," says William Schneider, a public policy professor at George Mason University.
Iraq was a leading political issue throughout the presidency of George W. Bush, especially after the lightning attack and quick march to Baghdad gave way to a violent insurgency.
The course of the war went a long way toward explaining why Democrats won control of both chambers of Congress in 2006.
"It's one of the reasons Obama won the Democratic nomination [in 2008]," Schneider says. "He opposed the war from the beginning."
But Iraq — and the ongoing war in Afghanistan, for that matter — barely rated mention in either the midterm elections of 2010 or the presidential campaign last year.
The political wound that was Iraq had stopped festering even before the U.S. presence there had ended, thanks to a decline in violence occasioned by an increase in the number of American troops — the surge — and other factors.
"This is not to minimize the costs that we paid in Iraq," says Rajan Menon, a political scientist at City College of New York. "But following Iraq is the financial crisis, and it displaced Iraq as the great trauma that befell America."
A Smaller War
As difficult and long-lasting as Iraq was, it did not compare in casualty count with Vietnam. More than 58,000 Americans died in Vietnam, compared with fewer than 5,000 in Iraq.
Also, there was a draft for Vietnam, meaning far more Americans went there — or feared they might — than was the case with the recurring tours of the all-volunteer force that served in Iraq.
"The fact that there was a draft during Vietnam meant that almost everyone in this country was affected by the war very directly," says Deborah Kalb, co-author of Haunting Legacy: Vietnam and the American Presidency from Ford to Obama. "Everyone was in the draft, or figuring out how not to go."
The draft made Vietnam a much bigger deal on college campuses than Iraq ever was and sustained a more robust anti-war movement.
Vietnam helped open rifts not only between generations, but also between the people and the government. Along with Watergate, it helped sour the nation on Washington and its political leaders.
"Vietnam created chaos inside the United States," says Kohn, the UNC historian. "American society was deeply affected by the experience of Vietnam, and not just the war, but its political and social contexts."
An Unambiguous Failure
Vietnam was a central battleground of the Cold War, a struggle between superpowers that lasted for decades.
"Part of the powerful narrative of the post-Vietnam syndrome is that it was experienced over a long period of time, under many presidents," says Menon, the CCNY professor.
Iraq, by contrast, was associated with a single president. And it doesn't seem to have been part of any grand strategy or larger geopolitical struggle.
Unlike the "domino theory," which held that if Vietnam fell to communism other countries would inevitably follow, there was no equivalent fallout from Iraq beyond its borders.
The Bush administration argued that Iraq was another front in the broader global war on terrorism, but there was no evidence that Saddam Hussein's regime had ties to al-Qaida or the attacks of Sept. 11, 2001.
"It became very hard, especially once the WMD [weapons of mass destruction] stuff failed to materialize, to convince large numbers of people that Iraq was vital to the national security of the United States," Menon says.
For all that, Iraq did not leave so bitter a residue as Vietnam.
"Very few are going to come forward and claim Iraq as a victory," Wohlforth says, "but it doesn't seem as unambiguous a defeat as Vietnam."
The War's Half-Life
The American intervention in Vietnam ended with the image of people desperately clinging to helicopters as they took off from the roof of the U.S. Embassy in Saigon in 1975.
It took years for the U.S. to shake off such images. It wasn't until 15 years later, with the first Persian Gulf War, that the country seemed ready to engage in a full-scale conflict again.
Vietnam had a longstanding political resonance, as well. Controversy surrounding his service there was one of the major reasons Massachusetts Sen. John Kerry, now secretary of state, was unable to unseat President Bush in 2004.
"For 20 years, one of the major themes was what did Candidate X do during the late 1960s, when they had the option to go to Vietnam or not to go," says Kalb, the author.
Interestingly, the presidential nominees who served in-country — Kerry, Al Gore and John McCain — all lost, while their generational peers who didn't go to Vietnam — Bush and Bill Clinton — both won.
Still, it's hard to imagine a presidential candidate or Cabinet nominee having to explain his or her position on the Iraq War 20 or 30 years from now.
It Takes Time To Seep In
But then, Vietnam wasn't all that much discussed immediately following its end. It wasn't until several years after Saigon fell that the major movies about the war, such as Coming Home, The Deer Hunter and Platoon, came out.
"There was an absolute will to forget about Vietnam," says Robert Brigham, a Vassar College historian who has written several books about both wars.
It's possible that we're still too close to Iraq to know what its meanings are for the country.
"It just takes awhile to get over the emotional exhaustion of the war and to be able to look more dispassionately at how this happened," says George Mason's Schneider. "It's a very bad memory."