With nearly daily bombings killing hundreds of civilians in Iraq and U.S. soldiers being targeted by "friendly" troops in Afghanistan, it is remarkable that many members of Congress want the United States to play an aggressive role in the Syrian civil war.

Sen John McCain has called for direct U.S. enforcement of a "no-fly zone" to protect Syrian rebels trying to take down the bloodthirsty dictator Bashar al-Assad, for example. And when the Obama administration announced that the U.S. would help arm Syrian rebels in response to the regime's use of chemical weapons, Sen. Bob Casey applauded but joined Mr. McCain in calling for more aggressive action.

Yes, the Syrian strongman deserves to be deposed, and the carnage has been horrendous - 93,000-plus confirmed dead by the United Nations. But a stroll through the alphabet - from Algeria to Zimbabwe - reveals a long roster of dictators who trample rights to stay in power.

As the United States learned in Iraq and Afghanistan, there is no bright line separating the good guys from the bad guys, no way to assure that the winners will embrace American ideals.

After many members of Congress mocked the administration for its "lead from behind" posture in the rebellion against Libyan dictator Moammar Gadhafi, which didn't cost one American life. Then, they excoriated the administration for the tragedy at the Benghazi consulate that resulted in the deaths of Ambassador Christopher Stevens and three other Americans. Now, many of those same members of Congress advocate plunging into a far more chaotic situation.

If America is war-weary, it is with very good reason. The administration should keep U.S. involvement in Syria as limited as possible.