If you look at the current Mosul campaign against ISIL, for example the few thousand troops that we have there to support that effort allows the Iraqi military to move forward in an effective way.
A lot of people change for good. Some people just fall off. Just trying to progress in anything, no matter what you're doing, I feel like any progression you make... some people aren't gonna be around you that were around you.
Here at home, we will strengthen our defenses but not succumb to a siege mentality that sacrifices the open society and liberties and values that we cherish as Americans, because great and proud nations don't hunker down and hide behind walls of suspicion and mistrust.