As a proud member of the Tiger Brigade of the 2nd Armored Division of the Army, I can say the Marines did not use M1 Abrams prior to Desert Storm. The Marines entered Desert Storm with M60 MBT's. Just prior to the start of the ground war, the Tiger Brigade was moved to support the 1st and 2nd MarDiv. The Tiger Brigade was a separate brigade in the war, and our post neighbors, 1st Cav, didn't want us to go into the ground war with them, so the Marines took us and we served them proud as they did us. I would serve with the Marines any day.