A U.S. Army war College study of the recent Iraq campaign concluded that without American precision weapons (smart bombs and excellent fire control for artillery and rifles), situational awareness (excellent reconnaissance and communications) and survivability (lots of armored vehicles and excellent flak jackets), casualties would have been much higher (5-10 times higher or more.) But the Iraqis still would have lost.
What enabled four coalition divisions to defeat 23 Iraqi divisions in three weeks was the poor quality of Iraqi training, leadership and equipment. This is why wargames analyze all the combat units involved and calculate actual "combat power", not just the number of troops and weapons each side has.
The coalition technology advantage enabled our troops to quickly exploit Iraqi sloppiness and mistakes. But it was also clear that against better trained, led and equipped troops, it would have been more of a slugging match. While "jointness" (the three services operating closely) was useful, it did not prove to be a decisive element. The Iraqis were largely beaten by brute force, applied at high speed and much skill.
As one American officer put it "There are some counterinutive premises here about speed and jointness, but the real message is understanding the military competency of the adversary. I remain "struck" (sorry about the double entendre) by the U.S. Air Force study reporting only 156 time critical strike targeting events during the campaign. Makes me wonder if we are spending a lot of time and money for a capability that won't be used very much."