re: A UN resolution
"The UN might agree if the US relinquishes its authority in Iraq and accepts a UN resolution demanding that all occupying forces be withdrawn from Iraq."
The coalition is the occupying power, this has been recognized by the UN.
There is no other countries other than the members of coalition is willing to have 100-200 thousand troops in Iraq. Withdrawing coalition forces from Iraq would be irresponsible; what you are proposing is simply foolish. If French want to send in a few thousand troops, they should probably instead put more troops in the Congo- millions are dying & it's a mess.