Kill Anything That Moves discussion

I haven't finished the book yet, so maybe this question is answered, but what I'm wondering is simply (too simply?) is why would the American government do this? Maybe this doesn't have a simple answer (I'm sure it doesn't), but was it simply an experiment in human conditioning? Was it essentially a way to create business for defense contractors (considering the laundry list of munitions that were used). We're they "true believers" in the cause to fight communism?

I know I'm over simplifying the question, but I'm curious as to what people think.