I have recently read that Iraquis are being killed while recovering scrap metal from unguarded arms dumps. In any event the country is awash with arms and ammunition abandoned by the defeated Iraqui army.
Thinking back to my own army service I cannot believe that a hostile element could not obtain the modern equivalent of the British three inch mortar and get off a significant number of rounds before being obliged to flee. Granted, the mortar is a spray and pray weapon and in military terms unlikely to inflict significant damage, but again in military terms, the safety standards that apply in aviation are fantastically high.
Baghdad airport is in a war zone and civilians flying into it should be paid accordingly. Even if their managers can see no danger from behind their desks in their home countries.