The "unemployed & desperate" and Nazi collaborators were not mutually exclusive categories. No occupation, fascist or colonial, can last even a second if only the ruling class collaborated with the occupier.
Colonialists and imperialists have employed native forces to keep natives under control throughout history, so when resistance to colonization arose, it was usually native forces, rather than colonialists and imperialists, who took the largest casualties. Take the Vietnam War, for instance, and compare the casualties of US and ARVN forces. The ARVN forces' casualties consistently outnumbered the US forces' casualties: <http://www.rjsmith.com/kia_tbl.html>. In 1972, the ARVN casualties were 100 times larger than the US forces' casualties.
Whether resisters expand their targets from native soldiers, "village guards," informants, etc. who work for imperialists to native civilians -- interpreters, day laborers, prostitutes, janitors, cooks, and so on -- who work for them and how much depend on the political programs of the resisters, but I can't think of any resistance in history that has attacked only combatants.
In any case, what Iraq needs is a charismatic nationalist leader who can win support of most or all major constituencies and of the governments of Iraq's neighboring countries. Only such a leader can defeat international jihadists and neutralize sectarian militias. Will Western leftists support such a nationalist leader if he turns out to be Moktada al-Sadr or an Islamist like him? -- Yoshie <http://montages.blogspot.com/> <http://mrzine.org> <http://monthlyreview.org/>