It's too early to say the U.S.-led invasion of Iraq has turned sour. But the classic headaches of a military occupation have come on with astonishing speed.Despite months of planning, U.S. forces have shown themselves to be confused about the transition from invading to policing, and unsure about what policing entails. Commanders have been wildly optimistic about the ease of setting up a transitional government. And many Iraqis are signalling that they plan to think for themselves when it comes to designing their country's future.Four weeks into the war, it's still unclear whether Washington is seriously looking for help in...