According to the international law of war, 'lawful combatants' are soldiers in uniform fighting for their respective militaries, while 'unlawful combatants' are people not in uniform who sneak into the opposing territory to wreak havoc.

'The spy who secretly and without uniform passes the military lines of a belligerent in time of war,' reads the 1942 US Supreme Court decision, 'seeking to gather military information and communicate it to the enemy, or an enemy combatant who without uniform comes secretly through the lines for the purpose of waging war by destruction of life or property are familiar examples of belligerents who are generally deemed not to be entitled to the status of prisoner of war, but to be offenders against the law of war subject to trial and punishment by military tribunals.'

http://1rev.net/archive/30-repub/repub_30_3.html

Но, в общем, иракцы могут рассматривать переодетых и замаскированных под штатских американских военных, как некомбатантов. С соответствующими быстрыми трибуналами и взводом расстрельщиков.