Tension Rises in Central Asia

Imagine how the U.S. would respond if nine American diplomats were slaughtered in Mexico, and you'll have some idea of the dilemma facing Iran. Afghanistan's Taliban militia admitted Thursday that it had executed nine Iranian diplomats captured in an opposition stronghold this summer. In the past week, Iran has massed 70,000 troops on the Afghan border and has vowed to avenge the killings, raising Western fears of an imminent war between the rival Islamic states. Reports of Taliban massacres in Afghanistan's minority Shiite communities add to the pressure on Iran to intervene, but its leadership is likely to proceed with caution. "Tehran will be extremely reluctant to get involved in the Afghanistan quagmire," says TIME Middle East bureau chief Scott MacLeod. "Iran hasn't yet fully recovered from its disastrous eight-year war with Iraq."

At the same time, Iran can't allow the killing of its diplomats to pass unpunished. And with Shiite civilians fleeing the Taliban's advance into opposition territory just across the border, Tehran will be obliged to at least keep rattling its saber.