That 1997 massacre represents just one charge from a new Human Rights Watch report detailing alleged war crimes by America's ally in Afghanistan, the Northern Alliance. Along with Amnesty International, the watchdog group is asking the U.S. to withhold military assistance to alliance forces until its leaders address past abuses and, ideally, bring to justice the four chiefs responsible for the worst horrors.

"The senior commanders are really beyond the pale," says Human Rights Watch's Joost Hiltermann. "These were commanders who were in charge when atrocities were committed."

This is hardly the first time the U.S. has gotten into bed with less-than-savory characters in the name of short-term strategic needs. During the '80s, the U.S. armed and trained Islamic fundamentalist guerrillas—including Osama bin Laden—to beat back the Soviet Union in Afghanistan.

Now the U.S. faces a similar loss of control with the Northern Alliance, a loose group of anti-Taliban fighters more properly known as the United Front. Dominated by ethnic Tajiks, Hazaras, and Uzbeks, the front has now entered the Afghan capital of Kabul, in the absence of a replacement coalition regime. That could leave the Bush administration open to the ire of its other key ally, Pakistan, which wants the next government to include the ethnic Pashtuns who make up some 40 percent of the Afghan population.

Already, there are reports of hundreds of summary executions and looting by victorious Northern Alliance troops.

The idea of halting the war to root out a few commanders for old accusations seems like folly to some Central Asia experts. "To just be focusing on past abuses—especially pretty far in the past, or abuses that are pretty minimal—that's not really what we should be doing," says Julie Sirrs, a former Defense Intelligence Agency analyst. "If allying with the United Front allows us to get the Taliban out of Afghanistan, I think that does far more in support of human rights overall."

Indeed, the Taliban is reported to have retaliated for the 1997 slaughter with a three-day rampage in which thousands of civilians were killed.

As the Human Rights Watch report demonstrates, the civil war compromised virtually every faction in Afghanistan. Hiltermann says the U.S. should at least try to pinpoint and isolate the worst offenders, but instead the White House has thrown in its lot with a rogues' gallery of brutal warlords. Their ability to govern Afghanistan humanely is, at best, dubious.