"Bring war materiels with you first, then forage on the enemy." -Sun Tzu
Sun Tzu always emphasized the need to be prepared to go to war at any time, be able to take with you what you need, and not have to return to resupply.
Defense Secretary Donald Rumsfeld made the decision to deploy mostly combat units in the weeks before the invasion, and held back Army and Marine Corps logistics and support units. Battalions of tanks and armored vehicles dashed forward in pursuit of the enemy, leaving behind a trail of broken-down vehicles because there were no repair parts. Some units even ran dangerously low on ammunition and had problems getting resupplied. Others that needed M-16 rounds received unneeded tank shells instead.
An important lesson, "Bring with you what you need," was not learned.
General Paul Kern noted in an interview that "American forces managed to prevail only because of the creative ability of individual soldiers to pull the pieces together. They are the heroes."
Bottom line: beware of Very Serious People. Don’t be in awe of them, for often they are stunningly wrong.