burning petrol, funds taken away from environmental/social projects at home, refugees exhausting resources, the irreversible damage done to alaska when the idiots in washington make a mess out of the middle east and/or iraqis destroy own oil sources, discarding and/or blowing to bitsies of tons of materials in planes, equipment, weapons plus destructive means of obtaining new materials (i don't think they're going to be doing any recycling over there).
this one may not be environmental but it bothers me: iraq is the cradle of civilization. the natural environment fostered the human race. i have a personal problem with blowing that up.