President Obama's vow to punish Syria for using chemical weapons has critics of U.S. foreign policy upset that America is yet again acting like an imperialist power. Their frustration is appropriate -- but their accusation is not.

America is less an imperialist and more a hapless uncle trying to teach his wayward nieces and nephews the right moral lesson. But just as with the uncle, no one will thank America if it averts further catastrophe -- but everyone will blame it if it doesn't.

It has become fashionable these days to talk about America as an imperialist power. But genuine imperialism involves exploiting others for one's own material interests. That's what British colonialists did when they took raw material -- minerals, fabrics, cash crops - from Indians at confiscatory rates for their factories back home.

Or when the Soviet Union transported Eastern European assets - coal, industrial equipment, technology, even personnel - to reconstruct the motherland after World War II.

The Soviets received a net transfer of resources from the rest of the Eastern Bloc roughly comparable to what "imperialist" America pumped into Western Europe under the Marshall Plan.

By contrast, America's post-Cold War efforts, with some notable exceptions such as Afghanistan, have been less about promoting its own vital interests and more about protecting others.

President George H. W. Bush sent American troops to Somalia in 1993 to stop a nasty civil war in which innocents were routinely butchered. The first Iraq invasion was launched to liberate Kuwait from Saddam Hussein and establish a loopy "new world order."

Bush's successor, Bill Clinton, dispatched U.S. military forces to Haiti in 1994 to restore an elected president ousted by a military junta. Bosnia and Kosovo operations were meant to protect Muslims from wholesale slaughter by Serbian tyrant Slobodan Milosevic.

Even the second George Bush's Iraq War was not about getting cheap oil, as is popularly believed. Otherwise America could have simply ended the oil sanctions against Saddam. Rather, the war was in equal measure a panicked overreaction to 9/11 and an effort to stop decades of human rights abuses by a ruthless dictator.

Some of these operations were more successful than others. But thanks to an inability to draw proper moral distinctions, America has received far more blame for the civilian casualties it caused than credit for the lives it saved. This blindness even afflicts "objective" research.

Consider the 2006 study in Lancet, a British journal, which cemented the notion that America was even worse for Iraq than Saddam. It surveyed Iraqi households and concluded that "an additional 2.5 percent of Iraq's population has died above what would have occurred without conflict."

But setting aside that 70 percent of these deaths were caused not by coalition forces but terrorists and insurgents, the bigger problem was that the study lumped combatants and civilians. But a war's very nature requires killing combatants to protect civilians.

By contrast, the Iraq Body Count that tracks civilian deaths with the express purpose of opposing the Iraq War estimates that the death rate during occupation (12,400 per year) was less than half of the death rate (29,000 per year) during 35 years of Saddam's rule.

None of this means that these efforts were justified.

For starters, the opportunity costs were massive. Even a relatively cost-effective intervention like Bosnia required $120,000 for every life saved, according to Dartmouth University's Benjamin Valentino.

Far more deaths would be prevented if this money were spent combatting measles ($224 per life saved) or malaria ($100 to $200 per life saved).

What's more, even when it comes to civilians stuck in violent situations, there is a less bloody way of helping than war: Bring them over! This will require working with international relief organizations to arrange evacuation.

It will also require knocking down immigration barriers against refugees - something even committed restrictionists have to admit is a far better option than risking American troops.

Perhaps the British parliament’s refusal Thursday will force Obama to look for these ways -- instead of launching another thankless war whose only guaranteed outcome is more egg on Uncle Sam’s face.

America needs saving from its impulse to save others instead of exploiting them.

Shikha dalmia, Washington Examiner Columnist is a senior policy analyst at Reason Foundation.