They resulted in tens of thousands of casualties throughout the country, killing and wounding civilians and combatants alike.
Many Iraqi insurgents favoured the tactic of suicide bombing, which was used at a particularly unprecedented scale against the American-led Multi-National Force – Iraq (MNF–I).
The main targets of these bombings were MNF–I troops and private military contractors, as well as local Iraqi collaborators.
"[3] A 2008 research brief by the RAND Corporation on the subject of counter-insurgency tactics in Iraq between 2003 and 2006[4] depicts a chart that shows that in June and July 2004, Iraqi insurgents began to shift their focus away from attacking coalition forces with roadside bombs and instead began targeting the Iraqi population with suicide bombers and vehicle-borne IEDs.
By increasing the number of suicide bombings against civilians and accepting their targeting in retribution, the insurgents sought to expose the weakness of the coalition's and Iraqi government's security and reconstruction apparatus, threaten those who collaborated with the government, generate funds and propaganda, and increasingly enact sectarian revenge.