While the US army, navy and air force cooperated well in the Iraq campaign, there will be less unity and "jointness" in the after battle analysis. It's expected that each service will disagree on who made how much of a contribution. The original concept was for "light forces" to blitz their way to Baghdad, take down Saddam's government and declare victory. It turned out that heavy forces were needed to do the job. The 3rd Mechanized Infantry division was the point of the spear. The divisions four tank battalions and five mechanized infantry battalions were largely immune to most enemy weapons (especially RPGs and artillery shells). The 1st Marine division had 11 infantry battalions, three tank battalions and two light armor battalions. But the marine amphibious armored vehicles were not as bullet proof or as durable as the army's M-2 Bradleys. The marine vehicles were not built for going that kind of distance in the desert. So the army took the long way, out through the desert, and arrived in Baghdad first. The marines went up the river valley, and put their amphibious vehicles to good use. But for speed, you needed the army's armor. The air force, using its Afghanistan experience, put a lot of bombs where people on the ground asked for them, as well as on targets spotted from the air. It did not turn out to be another Afghanistan, although the Special Forces psychological warfare efforts, including some negotiations, basically kept the Iraqi army out of the war. The 3rd Mech and the Marines took care of any Republican Guard that survived the smart bombs.
There's plenty of praise for all concerned. But the most relieved people are those that use tanks. Written off as "so 20th century" and given no place in future defense budgets, all of a sudden, heavy armor has suddenly gotten some respect. What this will translate into is hard to tell. But no one is going to seriously advocate going after a second or third rate army without a few hundred M-1 tanks on hand.