But, put yourself in the local's position. You have what amounts to occupational forces (foreign) telling you how to run your own country, interfering with day-to-day living and generally throwing their weight around. You are disgruntled but happy to keep your head down and out of the way. Then some arsehole bashes your pride and joy (you may have been saving for years just for the privelidge of driving a 'shitbox') - you're pissed off.
Who's side you gonna be on? It's this sort of arrogance that has lead to the 'war' continuing on well after the official overthrow of the ruling party (Hussein and his mob).
Instead of trying to work WITH the locals they are working AGAINST them yet demanding their support.
Have a look at the Dutch UN forces controlled area - far, far less bombings, shootings etc. then look at how they operate - WITH the local populace. Have a quick read http://www.timesonline.co.uk/article/0,,3-2533123.html