The second round of war with Iraq is learning from the lessons of the first. Less ammo will be brought in for a force that will probably not exceed 250,000. But another difference this time will be the increased use of the "air head." During the 1991 war, the 101st Air Assault division set up a supply base deep inside of Iraqi territory by flying troops to clear the area, then using C-130s and helicopters to move in supplies and additional troops. The helicopters and infantry then operated from that base, chopping up Iraqi units that did not expect to encounter American troops so soon, so far from the border. This time around, there will be more of those bases, sometimes using Iraqi air bases seized by American Rangers and commandos. These forward bases would be needed to provide a supply base for Iraqi opposition groups to get support (medical, weapons, ammunition, food) from.
Quickly establishing several bases deep inside Iraq serves several useful purposes. First, it unnerves any Iraqis determined to resist. This is what that base in the Iraqi desert did during the 1991 war. Next time around, any Iraqis attacking these bases merely attracts hundreds of warplanes carrying smart bombs. Meanwhile, the Special Forces, Rangers, commandos and infantry operate from these bases to go after Iraqi missile launchers, supply lines and nearby Iraqi headquarters, bases or airfields.
Meanwhile, American heavy forces (tanks and other armored vehicles) can roam over a larger area unseen by any Iraqis. Saddam will be sitting in his bunker even less unsure of what is going on than he was in 1991. That kind of uncertainty leads to bad decision making, and an increased possibility that Saddam's inner circle will see the errors of their ways and effect a change of leadership before American tanks, bombers or commandos show up and kill everyone in the bunker.
This tactic would use logistics as an offensive weapon in way it has never been done before. It's an opportunity that American military planners are apparently reluctant to pass up.
Logistics for an invasion of Iraq are probably going to be a bit different than the 1991 war in the Persian Gulf. Many lessons were learned in 1991 about supply needs for a war in the desert against the Iraqi army. First of all, not as much stuff will be needed. For the 1991 operation, some seven million tons of supplies and equipment were shipped in. That was for an American force of half a million. But of the 400,000 tons of ammunition brought in, 370,000 tons were sent back home after the war was over.