Editor's note: John Mueller is professor of political science at The Ohio State University. His book, "War and Ideas," from which this article derives, will be published later this year as will his book, co-authored by Mark Stewart, "Terror, Security, and Money: Balancing the Risks, Benefits, and Costs of Homeland Security."
(CNN) -- When the Gulf War began in 1990, many were worried about "another Vietnam," but few of those were in the military.
The war chiefly showed how easy it is to run over an enemy who has little in the way of effective defenses, strategy, tactics, planning, morale or leadership. When it ended, President George H. W. Bush, triumphantly exclaimed, "By God, we've licked the Vietnam syndrome once and for all."
Within three years, however, the country picked up another syndrome. A couple dozen American military personnel were killed in scraps of armed conflict while trying to police an anarchic situation in Africa. In consequence, Americans succumbed to the Somalia syndrome, and thereafter troops were sent into such situations only when the environment was "permissive" or when high altitude bombing could be relied upon alone.
And today we are living with the effects of an Iraq and Afghanistan syndrome, which is partly responsible for America's reluctance to intervene militarily in Libya.
In international politics, a "syndrome" can be defined as a general, even visceral, unwillingness, in the aftermath of a bad experience, to do anything that might lead to a repetition.
There was something of one after World War II, and it still shows signs of potency even two-thirds of a century later, confounding the many dire predictions over the decades that the syndrome would fail.
There was also a Korean War syndrome. In the aftermath of that costly experience, theorists viewed it as a harbinger and geared up extensively for another "limited war," a war like World War II but geographically constrained. Such a conflict never took place and the syndrome was probably a key reason why.
Above all, there was the Vietnam syndrome. The lesson learned was to avoid anything that looks like that kind of war, and counterinsurgency was substantially expunged from military training and theorizing. There never was another Vietnam for the United States during the Cold War.
The experience of 9/11 changed this in the sense that it brought out an enemy that the American public was willing to take on regardless of the costs -- though given how the war in Afghanistan turned out initially, the public's tolerance for U.S. casualties in that conflict was never tested.
With that encouraging experience under their belt and well remembering the splendid little war of 1991, American forces plunged into the war in Iraq in 2003. It began like the Gulf War, but then disintegrated into something like, but much worse than, Somalia. To top this, the occupation of Afghanistan soon began to look like another Iraq as dedicated insurgent forces became ever more threatening and capable.
Unlike the situation after Vietnam, military planners seem to be anticipating that the next war will be like Iraq and Afghanistan, and counterinsurgency has again become all the rage. However, whether there will be the political will to venture into experiences like Iraq and Afghanistan again is anything but clear. Certainly there is none for launching Iraq-style invasions of Iran and North Korea, and the reluctance to send troops into Libya is palpable.
In a speech in February at West Point, Defense Secretary Robert Gates said, "In my opinion, any future defense secretary who advises the president to again send a big American land army into Asia or into the Middle East or Africa should 'have his head examined,' as Gen. MacArthur so delicately put it,"
Actually there has never been much support for sending American troops into hostile situations in the last decades -- or maybe even century -- unless there was a decided provocation like Pearl Harbor or 9/11. By now even support for the once-popular, 9/11-induced war in Afghanistan is waning.
Since 1945, pollsters have periodically asked, "Do you think it would be best for the future of this country if we take an active part in world affairs, or if we stayed out of world affairs?" At the end of the century, the "stay out" option was chosen by 28%, something of a historical average. In the wake of 9/11, this number dropped to 14%, the lowest it has ever been. Since that time, however, the option has become considerably more popular, so that by 2006, the latest time the question was asked, fully 38% embraced the sentiment, the highest registered by the question.
This is not necessarily an indication that old-fashioned isolationism is emerging -- the United States is unlikely to withdraw from participation in the global economy or political organizations. But it could well be fertile ground for an Iraq syndrome, or an Iraq-Afghanistan syndrome, to flourish.
The opinions expressed in this commentary are solely those of John Mueller.