Initial press reports have suggested the battle has mostly come out a draw. But a 14-point "truce" between the government and the Mahdists (brokered last week by Iran) suggests otherwise. Among other details reported in the press, the agreement requires the Mahdi Army to abandon its heavy and medium weapons, end its shelling of Baghdad's Green Zone, shut down its kangaroo courts and recognize the authority of Iraqi law. In exchange, the government seems to have promised mainly that it would not arrest lower-level militia members.

The truce suggests, instead, that Iran has grudgingly come to respect Mr. Maliki as a serious opponent. Having invested itself so heavily in Mr. Sadr's success, Tehran had little reason to suddenly lend its diplomatic offices unless it felt the Mahdi Army was on the verge of defeat. Last week's truce may have postponed that moment, but there's little doubt Mr. Sadr's movement has suffered an embarrassing defeat.

However fitfully it began, the Basra campaign is a sign that Iraqis are in fact "standing up" for their own security. It is also a personal vindication for Mr. Maliki, who recognized to his credit that his government had to have a monopoly on violence in Shiite neighborhoods as much as in Sunni enclaves.

In the last year we were told first that the surge was a military failure, and later that it was a military success but that Iraq's political class had not lived up to its end of the bargain. In fact, just as surge supporters said, the Iraqis have become more confident and effective the more they have become convinced that the U.S. was not going to cut and run.