This isn't a good argument. The US has friendly neighbors on its northern and southern borders. It has thousands of miles of ocean separating it from Russia or China (neither of which have any major military blue water transport capacity). We could defend the US homeland with a tiny fraction of our current bloated 700+B / yr budget. That money could be going to fix problems that affect the common citizen rather than enriching the shareholders of defense contractors. I don't buy this at all.