Personally, the war in Iraq doesn't essentially protect the homeland. While I have an undying support for our troops, our efforts in Iraq serve a different purpose. Our homeland security is indeed benefitting from our endeavors in Iraq though; terrorism is more closely monitored, and with the inception of the insider act, our defenses have improved.
The war in Iraq is an example of United States interference in other countries' issues where we really have no business to be. The war was started on false premises and has caused loss of American lives and a drain on the economy with no perceivable benefit whatsoever. To make it worse, we didn't really help anyone, and the region now hates us for entering the country uninvited and slaughtering people that should have been managing their own issues in order to force a social order we prefer. We need to get out of Iraq and stay out.