How many days before we captured Baghdad in 2003? We did in fact reach our initial military goals in days and weeks. Record time, btw. What we did not plan for was the insurgents that started immediately. The military action to move and take Baghdad was as good or better that expected. Even with setbacks like out northern divisions being locked out by turkey at the 11th hour. Not to say we didn’t account for what’s next to the criticism of all levels on the military from planners all the way up to the White House.
That's what the Mission Accomplished banner behind Bush referred to. He was mocked ceaselessly for it by the Demonrats and the left when the insurgency erupted and our troops had to stay.