This is interesting.

Guardian Unlimited Observer | International | US 'to attack Iraq via Jordan' Although leaked Pentagon documents appear to show that Turkey, Kuwait and the small Gulf state of Qatar would play key roles, it is believed that Jordan will be the 'jumping-off' point for an attack that could involve up to 250,000 American troops and forces from Britain and other key US allies.
...

Iraqi dissidents in Amman have told The Observer that hundreds of American advisers have arrived in Jordan in the past few months.