American Troops Don't Know Who They are Fighting

How do you win a war when you can't tell who the enemy is:

The Washington Post reports that US soldiers in Iraq have a difficult task discerning enemy insurgents from friendly Iraqis.[...]Further, "many people in Baghdad express deep reservations about the Iraqi security forces' ability and desire to battle their fellow citizen," writes Joshua Partlow. US forces say Iraqi troops are "swayed more by the anti-American speeches of Shiite cleric Moqtada al-Sadr than by the public appeals of Prime Minister Nouri al-Maliki for even-handed enforcement."