If you decided to take a stroll in Central Park in Manhattan after midnight and ended up being assaulted, there is a good chance that you won't be taking that walk again anytime soon. Are you exhibiting the signs of a Central Park syndrome? Call it what you like, but you would be behaving in a rational way after learning from your experience: Don't walk alone in desolated urban areas late at night.

Similarly, the Munich and Vietnam "Syndromes" that afflicted Western elites and publics in the post-1945 era reflected the way some of the traumatic lessons of the history of the twentieth century provided basic rules for the American people and their leaders. Sometimes you have to stand up to and even use military force in dealing with aggressors, as with Munich. But on the flip side, don't rush into using military force in response to every real and perceived aggression, as learned in Vietnam.

Notwithstanding Munich, the United States didn't go to war against the aggressive Soviet Union and even tried to accommodate its interests, a practice also known as "appeasing." And despite Vietnam, the United States did pursue forceful military strategies in Afghanistan and in the two Iraq wars.

The lessons of Munich and Vietnam have been demagogued occasionally by both hawks and doves alike and used as political ammunition by leaders warning of "another Hitler" or "a new Vietnam." But there is no doubt that these lessons of history have been burnt into the minds of policymakers.

Ronald Reagan's advice, "trust, but verify" (as opposed to Neville Chamberlain's "trust and hug”), has become the guiding principle of American leaders when dealing with autocrats pursuing policies that harm U.S. interests. They also recognize that before going to war, they need to convince the American people that using military force is required in order to protect the nation's security.

But no post-1945 American presidents went to war in order to protect the citizens of a sovereign state against their government until the humanitarian intervention in the civil war in Yugoslavia. Nor did they attempt to remake the political and economic system of another nation-state based on U.S. values until the nation building of the second Iraq War.

It's true that during both World War II (when the United States was allied with the Soviet Union) and the Cold War (when Washington backed many oppressive autocrats), American leaders mobilized their people to fight tyranny and advance the cause of liberty. But it was the perception of the threat that Nazi Germany, Imperial Japan, or the Soviet Bloc posed to U.S. security and national interests that were the driving forced behind Washington’s interventions in hot and cold wars.

America did not set out to bring democracy to Germany or Japan, and could have probably coexisted with authoritarian-nationalist governments in Berlin and Tokyo that were ready to adhere to an international status quo that helped secure U.S. interests. It's also important to recall the United States refrained from going to war against the Soviets and ousting their dictatorship even when the Americans had enjoyed a clear military advantage.

Moreover, that both Bush administrations could win Congressional and public support for going to war against Iraq wasn't, as some suggested, an indication that the American people had overcome the Vietnam Syndrome.

The first Bush would not have won Congressional approval for the war just by comparing Saddam Hussein to Adolf Hitler and blasting his human-rights record. And the only reason a majority of Americans supported the second Bush’s attack on Iraq was their belief that Saddam had weapons of mass destruction (WMDs) that could be used against the United States. His invasion of Afghanistan was seen as an appropriate response to the 9/11 atrocities, whose perpetrators were headquartered in that country.

Indeed, it's difficult to imagine any scenario under which Congress or the American people would have given the White House a green light to go to war in Iraq and Afghanistan if President Bush had offered a different rationale: ousting from power a secular fascist regime that killed its people (Iraq) and a group of medieval theocrats who oppressed women and religious minorities (Afghanistan); transforming Iraq and Afghanistan into functioning liberal democracies through a long and costly process of "nation building"; and using them as models to remake the entire Greater Middle East.

Even if President Bush had provided empirical evidence and demonstrated beyond doubt that these proposed policies would succeed, prove to be relatively cost-effective and actually help protect U.S. strategic and economic interests, he still would have faced opposition. It’s doubtful that he would have won support from the majority of Americans and their representatives to go to war in the name of humanitarian intervention, nation building and his ambitious Freedom Agenda.

But after the destruction of Al Qaeda in Afghanistan and the discovery that there were no WMDs in Iraq, the American wars in the greater Middle East seemed to be driven by exactly by these elusive and idealistic policy goals that actually ran contrary to U.S. interests. Instead of helping maintain the order and balance of power in the Middle East, America helped ignite a civil war in Iraq, strengthened Hezbollah in Lebanon, allowed Palestinian Hamas to get elected, and engineered the election of an pro-Iran Islamist government in an Iraq that under Saddam had served as a bulwark against Tehran.

Ironically, the so-called Arab Spring seemed to have initially played into the hands of both liberal interventionists and the neoconservatives, who had been the intellectual force behind the Freedom Agenda, by creating a semblance of a rising wave of freedom and democracy in the Middle East. That in turn helped create the pressure for U.S. military intervention in Libya and bolstered calls for the same in Syria.

So unlike the lessons of Vietnam (don't rush to war), the lessons of Iraq and the ensuing efforts of humanitarian intervention, nation building and democratic crusades in the Middle East and its peripheries (the Balkans, South Asia) are complimentary, but different: the United States should only go to war to protect its security and its core national interests.

A majority of the American people have learned the latest historical lesson, have concluded that the Iraq War was a fiasco and that the United States has no responsibility to take sides in the civil war in Syria, and are clearly unimpressed by the calls by liberal and conservative interventionists—who insist that the United States not "stand idly," and that it needs to "do something" to stop the fighting there. Call it the Iraq Syndrome.

Leon Hadar, senior analyst at Wikistrat, a geostrategic consulting group, is the author of Sandstorm: Policy Failure in the Middle East.