The resistance to the US occupation of Iraq has defied most predictions in its duration, its intensity, its composition and its operations. General John Abizaid, commander of the US Central Command, has characterised the resistance as fighting a "classic guerrilla war" against the US-led coalition, led by "mid-level Ba’ath Party activists organised regionally together with foreign fighters".

The guerrilla campaign has persisted despite Saddam Hussein’s capture on 13 December 2003. The resistance has continued to demonstrate its ability to attack buildings and cause mass casualties, attack US forces and installations with conventional weapons, sack some local Iraqi governing installations, deter foreign investment and slow the pace of reconstruction.

One of the keys to understanding the resistance is analysing its motivations. From its inception, the resistance has represented an amalgam of motivations and goals. Some elements of the resistance want to restore the old Ba’athist regime, while others have been motivated by the goal of forming a Hardline Islamic state.

To accomplish those goals, all elements of the resistance hope to demonstrate that US stabilisation efforts are not working by causing international relief workers and peacekeeping forces to leave Iraq, slowing reconstruction, turning the Iraqi populace against the occupation and provoking civil conflict among Iraq’s various sects and ethnicities.

These efforts have led the resistance to aim at a wide range of targets: US forces; Iraqis and foreigners working for the Coalition Provisional Authority; infrastructure facilities; and symbols of the international presence, including the headquarters of the UN in Baghdad.

To date, resistance attacks have had only a minimal material effect on governance and the pace of economic reconstruction. However, the resistance has succeeded in creating a perception of chaos and a perception that US policy is in difficulty. The resistance has also caused the Bush administration to seek to minimise fallout in a US election year by accelerating the handover of sovereignty and security functions to Iraqis.