fear and respect
You have an interesting point. If we can give Saddam a year or more of warning, and still go in and kick his ass, it would make a very strong impression on a lot of people.
Saddam is no bin Laden. Bin Laden, assuming he's still breathing, has the potential of running his far-flung and loosely organized network from a trailer park. Saddam is head of a tight and formal organization, integrated with Iraq and its facilities. If he flees to Morocco, he's out of business in the leader department.
Again, interesting.