This from the LA Times

Abizaid, who is directing the war in Iraq, ordered commanders this week to craft plans in case conditions worsened and he called for more troops. As of Wednesday, he had not made that request of Defense Secretary Donald H. Rumsfeld, Pentagon spokesman Lawrence Di Rita said.

There are now 135,000 U.S. troops in Iraq, 20,000 more than called for under the current Pentagon plan because new units have arrived before those they are replacing have left.

But some soldiers who planned to depart soon have been ordered to remain on duty, Di Rita said. "At this moment, they're being used in combat activities," he said.

Asked if their yearlong tours of duty had been extended, he said, "Not yet."

In a briefing to Pentagon reporters Wednesday, however, Rumsfeld signaled that extensions were likely.

"We're taking advantage of that [temporary troop] increase, and we will likely be managing the pace of the redeployments to allow those seasoned troops with experience and relationships with the local populations to see the current situation through," he said.

Hmm? Did the U.S. provoke the showdown with Sadr at a time when they knew they had extra forces on the ground?