However , these initial counterinsurgency efforts failed to suppress the insurgency . The sweeps failed to stem the tide of the attacks , which during the summer of 2003 numbered about a dozen a day and resulted in , on average , 1 U.S. soldier killed and 7 more wounded every day . The guerrillas began adopting new and more complex tactics , such as the planting of IEDs ( concealed bombs usually placed on the roadside ) , the use of mortars , and better-planned ambushes . Although some humanitarian operations were included in what was intended to be a " carrot and stick " strategy , the cordon and search operations are widely criticized for being far too blunt and not carefully targeted . The large numbers of innocent Iraqis detained during the raids , the removal of palm trees and other foliage to deprive guerrillas of cover for ambushes ( and which represented the livelihoods of many farmers ) and the failure to restore basic services such as water and electricity to pre-war levels began increasing the nationalist resistance amongst the Sunnis and began resulting in the disillusionment of an Iraqi populace . In addition , as the summer neared its end , a series of suicide bombings began that suggested an increasing Islamist terrorist threats . The Canal Hotel bombing targeting the UN on August 19 , and the massive blast at the Imam Ali shrine that assassinated Ayatollah Mohammed Baqir al-Hakim along with dozens of others only ten days later marked the beginning of another phase to the conflict
Canal Hotel bombing
Canal Hotel bombing
Iraqi insurgency (2003–2006)