The suicide bombing campaign in Iraq became more lethal and frequent during 2006 as the Sunni-led insurgency and Al-Qaeda affiliated jihadist groups intensified their attacks on US-led troops, Iraq's Shia-dominated government, oil installations, police forces, and civilians. For a nation with no history of suicide attacks prior to the 2003 US-led coalition invasion, the intensification of the campaign since 2003 establishes the objective of the suicide terrorism campaign in clear terms as nothing short of a complete collapse of the current system and perpetuation of sectarian violence. It reflects the intensity of frustration and anger in a people that, despite their turbulent history of fight against occupation, had so far refrained from resorting to this extreme measure. In addition, it comes as a final blow to the US policy of regime change in Iraq through military invasion, and has further complicated the process of nation building.

The main target has undoubtedly been the coalition military forces, particularly US troops, thereby clearly reinforcing the prime objective of suicide attacks - to compel the coalition to withdraw its military forces from territory that the insurgents consider as their home, even as the UNSC extended the mandate of the multinational forces in Iraq for another year in November 2006. Further, a number of attacks on Iraqi forces, police officers, recruiting centres, and ministers in the Shia-dominated government indicate the use of suicide terrorism as a strategy to attack a government perceived to be under the control of the US. Some of the most ghastly attacks on the security forces include one in Ramadi on 5 January killing 70 soldiers, in Baghdad on 27 March killing 40 Iraqi soldiers, in Baqouba on 11 June killing 8 soldiers at an army check post, and in Baghdad on 13 November killing 35 Iraqi recruits.

There were also large number of explosions in busy thoroughfares such as market areas, mosques, shrines, and funeral processions. This is reflective of the increasing level of sectarian violence in Iraq with most attacks being perpetrated by Sunni Arabs in Shia enclaves, notably Najaf (site of the holiest Shia shrine), Sadr city (stronghold of Shia rebel cleric Moqtada Sadr's Mahdi Army militiamen), Kufa, Kerbala and Tal Afar districts of Baghdad. Major attacks include one by Sunni Arabs using three suicide car bombs and two mortar rounds on the Sadr city slum killing at least 160 people on 23 November, an attack on a Shia mosque on 29 December killing 10, a suicide car bomber killing seven people in a crowded market in the holy Shia city of Kerbala on 9 December, and a double suicide attack killing 22 people at a market in a Shia district in the northern city of Tal Afar.

A study of the attacks reveal that among the two essential weapons of suicide bombing, the use of a vehicle was dominant in attacks against civilians in crowded areas and against patrolling convoys whereas the use of an explosive belt directly attached to the human body was largely used in attacks on army bases and checkpoints. The reason behind this is simple: the scale of damage caused by car bombs exceeds that of human explosions, and thus, their use in crowded areas. On the other hand, it is easier for human suicide bombers to penetrate through army checkpoints and bases, than car loaded with explosives.

A cursory glance at the attacks substantiates this, for it clearly establishes that the attacks that proved to be the most lethal were the ones carried out in open public areas like markets through suicide car bombs. Attacks in a market in Kirkuk on 13 June killed 36 people; in a Shia street market in Baghdad on 1 July killed 62 people; in Sadr slum city in Baghdad on 23 November killed 160 people; and an attack on Shia laborers in Baghdad on 12 December killed 71 people. Significantly, this stands in contrast to the trend in the suicide attacks in 2005, with the most lethal attacks being those carried out against security forces, such as an attack on a security force convoy on 5 January killing 21 people, an attack on police and army recruitment centre on 28 February killing 125 people, an attack on a police recruiting centre on 4 May killing 60 people, and an attack on an army recruiting centre on 30 July killing 52 people.

It is clear that sectarian violence caused the largest number of Iraqi civilian casualties in 2006. Such attacks are believed to be the work of remnants of the Ba'ath regime, which, in turn contradicts the widely held perception that suicide bombing is the main modus operandi of fundamentalist jihadis alone. Moreover, the execution of Saddam Hussein is likely to accelerate sectarian violence still further. This also establishes that conflict in Iraq is as much about the struggle for power between minority radicals and majority moderates as about opposition to western forces. These two facets, however, are not mutually exclusive and can be said to form two sides of the same coin, for it is likely that Sunni insurgents are dragging the Shias into a civil war in order to make Iraq ungovernable for the Americans and to thus drive them out of Iraq.

Baghdad remained the most severely hit by suicide attacks and this focus on the capital further illustrates the objective of the insurgency to undermine confidence in the government. The remaining attacks were evenly spread across Kurdish north and Shia south.

It is worth noting that a striking factor of suicide bombing in Iraq is the lack of clarity on the origin and nationality of the suicide bombers. While members of the Iraq National Congress claim that Iraqis do not undertake suicide bombings due to their culture, insinuating thereby that the suicide bombings must be the work of foreign jihadis that have infiltrated Iraq, the familiarity of the targets chosen by suicide bombers throws doubt on this assertion.

The growth of suicide terrorism in Iraq is a critical issue not only because of the formidable challenges it poses for the US-led coalition and the Iraqi government in controlling the spread of this phenomenon, but also because of its tremendous psychological impact in perpetuating an atmosphere of fear and mistrust. As this atmosphere threatens to shape the people's psyche for the worse, the intensification of the campaign might have pushed the Iraq conflict further from resolution.