"the interim government in Iraq is not capable of defending the country against the terrorists"

No, and neither was the previous Iraqi government (under Saddam) capable of defending the country against the terrorists, who practice "Shock and Awe" tactics...who possess vast military forces and fleets of aircraft carriers...who drive Hummers, Abrams tanks, and Black Hawk helicopters and take their orders from Washington. Nope, the terrorists have proven a bit too well-armed and well-funded for any Iraqi government to deal with, and they have created a hell on Earth in that country. It is reminiscent of the situation in Poland in 1939-45. Call Baghdad the New Warsaw.