Before the Iraq campaign, the U.S. Marines were planning a new generation of armored vehicles to replace the 400 M-1 tanks and 800 LAVs (wheeled armored vehicles) they currently have. The idea was to use lighter vehicles (ten ton LAVs and 30 ton tanks) and depend on speed, superior communications and sensors to provide the same degree of protection the current heavier vehicles (15 ton LAVs and 645 ton M-1s). But after seeing all the dents and dings on their M-1 tanks, attention has shifted to developing lighter weight armor that will provide the same kind of protection the M-1 currently has. A major problem with the M-1 is that it burns over 30 pounds of fuel for each kilometer traveled. And the 120mm gun means only 40 rounds of ammo are carried, so a smaller caliber weapon would be nice, or maybe just missiles. It has long been thought that more agile, and better networked, armored vehicles could do things the current generation could not. Iraq provided a large scale experiment in what really happens. The networking does help, but it doesn't eliminate all the ambush situations. You still need as much armor as you can get for those worst case situations. And these happen more than you would like, and despite strenuous efforts to avoid them. So, after a reality check, it's back to the drawing board. Keep in mind, however, that most armored vehicles developed in peacetime do not benefit from much reality check. That explains a lot.