Whoops. Missed that.
Thought we were on the link subject (WWII), and I whiffed the obvious date in your post. Sorry.
The idea I was trying to get across is that if there are still troops stationed in Iraq a few years down the road, that doesn't, on its own, make it an occupation, although certainly our enemies will characterize it as such.
As for being responsible for security, I wonder what our troops in Germany would have done during the Cold War if suddenly East German terror groups started blowing things up in a major way, including NATO facilities.