Yeah, you'll still have the al Qaeda punks to find and we'd have to pick them off...that jerk in Syria may still have to dealt with, but he really is small potatoes. You'd see a lot of the $$ dry up for Hezbollah and Hamas...I doubt the Saudis would fund a lot of that terrorist crap if they see Iran fall.
We're trying to do that in Iraq and it is taking longer because you are constantly infiltrated by the enemy.
Easier said than done.