Even if the military situation in Iraq has improved since the U.S. added 30,000 soldiers to its forces there, the political situation just continues to deteriorate. Turns out that the State Department's Bureau of Diplomatic Security granted limited immunity to Blackwater USA employees being investigated by U.S. and Iraqi agencies over their conduct in a now-notorious Sept. 16 shooting incident in Baghdad. The immunity means the bodyguards could escape prosecution if it turns out, as seems likely, that Blackwater guards opened fire on Iraqi civilians without cause. The Sept. 16 incident outraged the Iraqi government, which is trying to kick Blackwater out of the country. But what should worry Americans is that no one seems to know who authorized the immunity, and how administration officials can continue to insist that anyone found to have committed a crime will be prosecuted.