Saudi Arabia is our big oil friend. Invading them makes about as much sense as shoving a pencil in your eye. It's just one of those things you don't do.
Like I said, Pakistan has no problem because they're our new buddies. I'm not saying it's right or wrong, but <b>that is the way it is</b>.
I gave a really short overview of why we can't attack DPRK
here. It is by no means exhaustive, but should be a good overview.
Personally, I'm not at all looking for a war. I am not at all convinced we need to be attacking Iraq. I also have a friend that's been called up (as has Cellar user Tobiasly), and I'm not at all interested in hearing that they're coming home in boxes. I'm just trying to look at this from a realist perspective. If we are going to attack someone, Iraq is probably the best option. :\