Killing Saddam Hussein, or at very least bombing him out of his palaces and into hiding -- which would also achieve the stated aim of regime change -- is, militarily, a trivially easy task for the United States. The problem is, we are afraid of what will happen if we kill him. And no wonder:
THIS IS NEXT
WE HAVE THIS ANTHRAX
YOU CAN NOT STOP US
Strongly encouraging Sadam to leave for a safe harbor isn't with precident. VD Idi Amin went into cushy exile in Saudi Arabia after things got too hot for him in Uganda. Napolean was exiled to St. Helena. Clinton was exiled to NY. Sadam would fit right in if he were persuaded to go to Zambia. ;)