A Showdown in Tehran

THURSDAY will be a crucial day in the Obama administration's attempt to stop Iran from acquiring nuclear weapons. No negotiations are scheduled, and the "crippling sanctions" President Obama promised in the absence of diplomatic progress are a ways from approval by the U.N. Security Council. But Feb. 11, the day when Iranians celebrate the 1979 overthrow of the shah, has emerged as another test of strength between the regime of Ayatollah Ali Khamenei and the opposition Green movement. The government has been trying to crush the rebellion with brute force. If it once again fails to stop thousands of protesters from taking to the streets of Tehran and other cities, the West will know that the extremist group that stands behind Iran's drive for the bomb is one step closer to collapse.