I just like explosions and giving our troops weapons that wont kill them.

As for the morality of mortality rates; if you desire any long term relations with the country you just invaded you generally need to leave it in a reasonable state, people get real touchy about showering their cities in hundreds of tonnes of toxic waste. Poor relations, usually ends with blowing each other apart again at some point in the future. Paying the premium now, saves money(and lives) in the long term. Not saying if we hadn't used DU, it would solve all the middle east's problems, but it's continued use, is one more short sighted decision that will bite us in the rear, militarily, diplomatically, financially or simply by incentivising a few more impressionable minds into killing innocent people.