Iran: Tehran vs. The Taliban

Iran and Afghanistan, two of the most profoundly fundamentalist Muslim countries, sit side by side, but common faith doesn't make them friendly. In fact, each despises the other's brand of Islam. Now Iran's Shi'ite leaders and the Sunni Taliban militia that has nearly succeeded in imposing its rule over most of Afghanistan are threatening to turn an ancient theological schism into a fighting war.

The immediate provocation is nine dead Iranians, killed last month when Taliban warriors conquered Mazar-i-Sharif, a stronghold of Afghanistan's Shi'ite community. Only last week did Taliban leaders admit that eight diplomats and a journalist holed up...