That is one big difference right there. U.S. field commanders are empowered to make decisions on their own in order to adjust to rapidly changing battle conditions. Iraqi field commanders are used to taking orders from the top and when they are on their own and out of communication with Saddam, they are crippled. Of course, there are many factors but this is an important one.
Take it down a few notches more, we train our youngest soldiers to become leaders, to take initiative. I have served as an escort officer for deligations of foreign officers and civilian leaders. Many are clueless about the NCO corps. They cannot comprehend what an NCO does. They have no idea of the authority given to a second lieutenant. Our youngest NCOs and junior officers impress these folks to no end! That is our secret! We train our soldiers, from top to bottom, to think and take initiative!