If the Obama administration steps up involvement in Syria and sends boots on the ground to support the rebels, Washington will be siding with forces reportedly responsible for this:

A rebel mortar attack on a school outside Damascus on Tuesday killed 29 people, Syria’s state news agency SANA said. According to the report, 28 students and one teacher were killed at the school in Wafideen Camp, in the Damascus suburbs.

Thousands of Islamic jihadists are now joining these rebels. These would be America’s allies by circumstance in any intervention against Assad. It would not be the first time that America’s policy, guided by “the enemy of my enemy is my friend,” carried with it such perverse results.

The United States supported Stalin in World War II, even sending back to him a million or more refugees to enslave and kill. The logic of the Cold War led the U.S. to back awful regimes in South Korea and South Vietnam, killing squads and dictatorships in Latin America, and ruthless killers in the Middle East, including Saddam Hussein and the future Taliban. The Carter and Reagan administrations even supported Pol Pot, perhaps the most terrifying communist of all, against the Vietnamese.

Just in the last fifteen years, the U.S. government has had its share of nasty wartime bedfellows. The United States sided with Islamist extremists in the Kosovo war, even taking the murderous KLA off its terrorist watch list. America conspired with the brutal Northern Alliance, implicated in crimes of rape, torture, and human rights abuses, to battle the Taliban and round up innocents to lock up at Guantánamo. The Iraq war elevated to power a new regime founded in socialism and sharia law, and depending on the chapter of the war, the Bush administration found itself aiding Shiite warlords or Saddam-era Sunni Baathists. Last year, in Obama’s Libya war, the United States supported forces tied to al Qaeda and unleashed massacres upon black Libyans.

As is usually the case in foreign conflicts, there are at least two unsavory sides. One might be much worse in practice, usually because it is in power, but once the weaker group comes to power, we see it is rarely much better than what it replaced. The U.S. has sided with some of the worst rebels and regimes throughout the last century. If Obama decisively commits significant intervention in Syria, we’ll see the pattern repeat itself all over again.

UPDATE: The death toll in the school bombing has been revised downward to ten.