By 2006 there was an extremely violent sectarian civil war in Iraq, with as many as 2700 to 3800 civilians being killed every month in the period from September 2006 to January 2007 with death squads roaming the streets of Baghdad. In addition to civil war, there was a nationalist uprising against the foreign occupation, which by late autumn 2006 caused the US army 100 killed and 700 wounded on a monthly basis. In response to the increased violence, the US government decided to send five additional brigades to Iraq, Baghdad being the main focus for the forces that arrived in the spring of 2007.
During the period of the “surge”, especially in the second part of 2007, violence decreased. By December 2007, the monthly average of Iraqi civilian deaths was approximately 500, while US army fatalities had shrunk to 23 killed per month. In this essay I will assess why the US “surge” in Iraq succeeded and how successful it was. Because I define the success of the “surge” as the tactical success of reducing attacks and deaths in Iraq, I will focus on explaining why the level of violence in Iraq went down during 2007. I will argue that the US “surge” alone is not a satisfactory answer to this question. To explain why the “surge” succeeded, I will assess local factors specific to the conflict in Iraq, which interacted with the “surge” and helped bring about its success. Shiite victory in the Iraqi civil war, the defeated Sunni's decision to cooperate with the Americans in fighting extremist groups and the ceasefire of the Mahdi Army, will be evaluated as other factors that can be argued as being of equal importance to the US “surge” in reducing the violence in Iraq.
Due to the limited length of this essay and many factors involved in the reduction of violence during the “surge”, I will focus primarily on why the “surge” succeeded, and will not look in-depth at the policies from 2003-2006 that led to the chaotic situation before the “surge”. Moreover, because it is out of the scope of this paper, I will not provide a broad assessment of Iraqi political progress or a detailed discussion of counterinsurgency on a tactical level. To summarize, in this paper I will argue that the “surge” itself was not successful; rather, a number of factors, in combination with “the surge” led to the reduction in violence in Iraq during the US “surge” period from February 2007 to July 2008.
Definition of central concepts
The “surge” will in this text be viewed as both the increased number of US nearly 30 000 troops in Iraq, and the change in the American counterinsurgency strategy to focus more on protecting the Iraqi population. The “surge” brigades arrived between February and mid-June in 2007, and the last of the five extra combats brigades had been withdrawn from Iraq by July 22, 2008. 
To overcome regional and sectarian limitations and provide a broad view of the events taking place during the “surge”, the term ‘Sons of Iraq’ will be used to refer to both the Iraqi Sunni tribal revolt against al-Qaeda and other Sunni extremists – often called “Anbar Awakening”, “Sunni Awakening”, or “Sunni tribal revolt” – as well as the Shi’ite revolt against Muqtada al-Sadr’s Mahdi Army during the same period.
The final concepts in need of definitional clarification are the extremist groups; in this paper Sunni extremists include Al Qaeda in Iraq, which had foreign elements in its ranks, as well as local Iraqis. Shi’ite extremists include the different Shi’ite militias, but refer specifically to Muqtada al-Sadr’s Madhi Army, which was established in August 2003.
Dynamics of sectarian conflict in Iraq 2003-2006
The nationalist insurgency in Iraq was provided with a surge in momentum, and a recruitment pool from which to draw upon, when the Iraqi army was disbanded in 2003. The British Iraq-expert Toby Dodge illustrates how unprepared the US was for the occupation of Iraq by the almost astonishing fact that Jay Gardner, the American who was selected to lead post-war reconstruction of Iraq, arrived without a professional Arabic interpreter or translator on his staff. The failed counterinsurgency effort to defeat the nationalist uprising in this period was mainly focused on killing or capturing insurgents. Indeed, as the British brigadier Nigel Aylwin-Foster notes, only 6 per cent of operations between May 2003 and May 2005 focused on protecting the Iraqi population.
Arguably, the civil war that developed in parallel with the nationalist insurgency resulted, at least in part, from the shift in the balance of power in Iraq. The Sunni-dominated regime of Saddam Hussein was replaced by a Shiite-dominated government, following the Sunni-boycotted election of 2005. Both Shi’ite and Sunni extremists groups played a dominant role in the cyclical dynamics of violence leading to the civil war as well. Counterinsurgency theorist David Kilcullen describes the cycles of violence in which Sunni extremists used intimidation to gain a foothold in Sunni areas, from where they launched attacks on Shiite areas. In turn, Shiite militias would respond by targeting the Sunnis of the area as a group, leading to tit-for-tat sectarian attacks and further polarizing the two communities.
This dynamic is illustrated by the bombing of the Shiite Al-Askariya Shrine in Samarra on February 22, 2006. Within hours of the bombing, 30 Sunni mosques were attacked in retaliation for the bombing. By the end of March the same year, 600 Sunni bodies were found on the streets of Baghdad. As the cycle of violence progressed, secular Sunnis and Shiites, lacking genuine security from the government, came to support the sectarian militias. This dynamic was exacerbated by the United States’ steady transfer of power and responsibility to the Shiite-dominated Iraqi government, despite obvious signs that the government was acting as a sectarian player in the vicious civil war.
Shiite victory in the Iraqi civil war as a cause for the reduction in violence
One factor leading to the decline in violence in Iraq 2007, as described by one American officer, was that the militias simply ran out of people to kill. Sectarian conflict had significantly reduced the ratio of Sunnis to Shiites in the Baghdad, leaving many dead and forcing others from their homes for fear of sectarian reprisal killings – in essence, the conflict had led to ethnic cleansing in parts of Baghdad.
The Gulf/2000 project's maps of the ethnic composition of Baghdad illustrate the new Shiite domination of the Iraqi capital, especially when comparing the maps of 2003 and early 2007, which saw a large number of formerly mixed neighbourhoods ending up with a Shiite majority. Even some formerly majority Sunni neighbourhoods ended up being inhabited almost only by Shiites. Judging by the criteria of territorial expansion in the Iraqi capital, the Shiites won the civil war. When comparing the maps of early 2007 and 2009, there are only minor changes in the ethnic composition of Baghdad, indicating that most of the cleansing was completed before the US “surge” troops arrived. The effect of cleansing was reinforced in some areas by concrete security walls separating Sunni and Shi’ite neighbourhoods.
The scope of the sectarian violence in Iraq up to early 2007 is illustrated by UN estimates of Iraqi refugees; a UN report from January 9 2007 estimated that 12 per cent of the Iraqi population had fled their homes. The estimated number of internally displaced Iraqis in January 2007 stood at 1,7 million, while estimates of the number of refugees in neighbouring countries ranged from 1,3 to 1,8 million. 2006 was also the year with the highest number of civilian deaths during the conflict in Iraq, with a documented total of 29,011 Iraqi civilians killed. 
The Shi’ite victory during the civil war, and thereby the reduction in sectarian violence, must also be understood in the context of the new Iraqi government’s role as an actor in the sectarian struggle. This is especially so for the forces of the Iraqi Interior Ministry, which gained a reputation for their brutality at the start of the civil war. David Ucko traces the link between government forces and Shiite militias back to the initial phase of the occupation, when Sunni militia and tribal groups were not included in political incorporation of militia leaders. The Sunni's weapons were also confiscated, while the Kurdish and Shiite militias operated at will. Ucko argues that this favouritism and rushed accommodation of the Shiite militias, was a large source for the later challenges the Americans faced in Iraq.
Nir Rosen demonstrates the dynamic connection between the Iraqi police and the Shiite Mahdi army militia, showing that most poor Iraqi Shiite men supported Muqtada al-Sadr, and most Iraqi policemen were poor Iraqi Shiite men. Sunni resentment towards the Iraqi police is illustrated by the U.S. Lieutenant Colonel James Crider, who observed that the credibility of the Americans troops went up as soon as they stopped bringing along Iraqi police forces on patrols. Losing the civil war, the Sunnis needed new allies.
The “Sons of Iraq” as a cause for the reduction in violence
In their recent journal article 'testing the surge', Stephen Biddle, Jeffrey A. Friedman and Jacob Shapiro examined a number of significant activities – defined as the use of force by any actors in the conflict – in Iraq's 38 areas of operations, in relation to the formation of “Sons of Iraq”. They found that violence was reduced faster in 24 of the 38 areas of operations after “Sons of Iraq” groups were established in the area, with the average reduction of significant activities for all 38 areas going from 2,5 per cent to 5,8 per cent per month.
The formation of the “Sons of Iraq” can explain this reduction of significant activities in two ways; for the nationalist insurgency, former insurgents switching sides from targeting Americans to working alongside them against the extremists would naturally lead to reduced attacks on American forces. Secondly Sunni “Sons of Iraq” groups could also help reduce attacks against civilians, by creating deterrence for the Mahdi army targeting Sunni civilians.
When former insurgents and civilians joined “Sons of Iraq” groups, this was a reaction against the extremists, not an action in support of the American forces and the Iraqi government. David Ucko notes that the extremist's efforts to integrate among the Sunnis of Iraq backfired; for example disagreement over lucrative smuggling routes and marriages were cited as a serious point of disagreement between the groups. A survey among Sunnis in August 2007, in the middle of the US “surge”, shows that Sunni’s were not suddenly keen on the American presence; only one per cent responded that they supported the US presence, 95 per cent said U.S. presence made security worse, and 93 per cent supported attacks on American Soldiers. Thomas Ricks describes a conversation between an American soldier and a former insurgent turned “Sons of Iraq” member where the US soldier ask the former insurgent if he wants to kill him, and is told 'Yes, but not today'.
Despite the American presence being very unpopular, The American Officer Gian P. Gentile concludes that the Sunni insurgents realised they could not fight against the extremists, Shiite militias, the Shiite-dominated government and the coalition forces at once, therefore they choose to deal with the Americans. It is arguably imperative to see the “Sons of Iraq” groups, which were formed in all 38 areas of operations in the period between October 2006 and May 2008, in relation to the Sunni loss in the civil war that seemed clear in late 2006.
The US “surge” as a cause for reduction of violence
When Ricks enumerates his explanations for why violence declined in Iraq, his first and clearest reason for reduced violence is the new American focus on protecting the Iraqi people. The claim that the counterinsurgency focus now was on protecting the Iraqi population can be criticized by the number of civilians killed by air strikes, which increased from 250 in 2006 to 940 in 2007. The number of US Special Operations Forces also increased to 5000 by the summer of 2007, leading to a very intense capture or kill campaign against both Sunni and Shiite extremists. U.S. Colonel Craig A. Collier argues that it was actually this targeting of insurgents that lead to a reduction in violence in Iraq, not efforts to protect and support the Iraqi population.
A criticism made of the US “surge” as the cause of reduction of violence in Iraq, is the claim that the US “surge” had little overall effect on violence. Gentile describes the thesis of military actions by US as the main reason for the reduction of violence in Iraq, as 'hubris run amuck [sic]'. The study by Biddle, Friedman and Shapiro does to a certain degree support the claim that the US “surge” did not break the insurgency by itself, since it shows that violence was at 97 per cent of the pre-surge level, until the “Sons of Iraq” groups was formed. Therefore it would be hard to claim that the former Sunni insurgents switched sides because they were defeated by the US “surge”.
On the other hand, there are also arguments in favour of the US “surge” as an important factor behind the reduction in violence in Iraq. The American officer James Crider emphasises that the new focus on protecting and building contacts with the Iraqi population led to gains in actionable intelligence, with arrests of suspected insurgents increasing from 16 in the first month of their tour in Iraq to 90 in their fourth month. Biddle, Friedman & Shapiro argue that the Sunni tribes had tried to turn against the Sunni extremists earlier in the conflict, but had been brutally defeated by counter-attacks from extremist groups.  The cooperation between the ”surge” forces and the “Sons of Iraq” aided the newly-turned former insurgents, enabling their survival and leading to a reduction in violence in Iraq. 
The role of the Mahdi Army in the reduction of violence in Iraq:
The Iraqi civil war, the “Sons of Iraq” and the US “surge” all had an impact on al-Sadr's Mahdi Army. Extra US forces freed up after the alliance with the former Sunni insurgents targeted the Mahdi Army, arresting or capturing senior figures in the group. This resulted in leadership changes in the Mahdi Army, with new, more radical and brutal leaders emerging to take the place of moderating elements, leading to a loss of popular support. Kilcullen emphasises that after the “Sons of Iraq” movement reduced the threat from Sunni extremists, the Mahdi army lost some of its appeal with the Shiite population. The Americans saw a split in the al-Sadr’s movement as an opportunity to support the moderates and target extremists, with some Mahdi Army moderates even getting paid by the Americans to provide security. The Mahdi Army also faced a new potential threat after violent clashes with the rival Shiite militia The Badr Brigade. Overall, these changes in the Mahdi Army’s strategic position led the group’s leadership to opt for a temporary ceasing of fighting.
Statistics for both American military deaths and Iraqi civilian deaths implies that al-Sadr's decision to declare a ceasefire in August 2007 had an effect on the reduction of violence in Iraq. In July 2007, 73% per cent of US casualties had come from combat with Shiite fighters. The timing of the cease-fire in relation to the level of civilian deaths in Iraq is also noteworthy, with the cease-fire being declared in August 2007, and the numbers of killed civilians declining rapidly the following fall. Biddle, Friedman and Shapiro's study also points out that in mid-2007 the Mahdi army was advancing towards new mixed and Sunni neighbourhoods in Baghdad. Hence before the cease-fire, there was potential for full-scale civil war to reach the heights of 2006 yet again. Nir Rosen goes as far as to describe the Mahdi army cease-fire as the single most important factor in reducing violence.
The role of regional actors in the reduction of violence in Iraq:
Kilcullen argues that the conflict in Iraq had to be seen in conjunction with a broader regional conflict between the Sunni Arab states and Shiite Iran. Iraq's switch from Saddam's Sunni-dominated regime to the new Iraqi Shiite-dominated regime, naturally led to a change in the regional balance of power.
Burke notes that Iraq's neighbouring states played a role in reducing violence. Syria and Saudi Arabia restricted the number of fighters that passed through their territory and into Iraq, amongst other reasons fearing violence inside their own borders. Jordan had already experienced a spill over from the conflict in Iraq with terrorist attacks in Amman and their intelligence services were targeting extremist groups connected to Iraq. Iran was cautious in their supply of weaponry to the Shiite militias, which were not given the same advanced weaponry that Hezbollah received in Lebanon.
How the causes for reduction in violence in Iraq are linked together:
Having looked at five different causes for declining violence in Iraq during the US “surge”, it is of interest to analyse how these causes can be argued to interact. Biddle, Friedman and Shapiro argue in their conclusion of “Testing the Surge” that a combination of factors led to violence being reduced in Iraq, but limit them to the US “surge” and the formation of the “Sons of Iraq” groups, while also acknowledging the effects these two causes had in putting pressure on the Mahdi Army. It can be argued that other causes for declining violence can be linked together with those suggested by Biddle, Friedman, and Shapiro; specifically the civil war, and the role of regional actors.
To summarize the chronological links of the causes, first the civil war outcome pushed more Sunnis into the “Sons of Iraq” groups. Secondly the US “surge” with new tactics and extra troops helped the “Sons of Iraq” survive counter-attacks by Sunni extremist's forces. Thirdly the “Sons of Iraq” switched many nationalist insurgents from being enemies to at least temporary allies of the Americans, thus freeing up American forces to target extremists. This pressure reduced the Sunni extremist's capacity to conduct attacks on the Shiites, which again decreased the popular support of the Mahdi army. This loss of legitimacy and US forces targeting the group, led the Mahdi Army to declare a cease-fire, potentially regionally linked with some Iranian influence behind al-Sadr's decision. At this point violence in Iraq was dropping fast. When seeing the causes for reduction of violence linked in this way, the timing of the US “surge” becomes critical for it succeeding, and Burke believes that if it had been tried six months earlier it may not have worked.
How great was the success of the US “surge”?
When assessing the success of the “surge”, it is important to note that while violence in Iraq was reduced significantly during 2007, Iraq continued to see regular attacks against US troops, Iraqi troops and Iraqi civilians also after the tide of violence was turned in the autumn of 2007. Even five years after the “surge”, more than 4000 civilians have been killed this year, with the number of Iraqi civilian deaths for 2012 the highest since 2009. It is also worth noting that the new level of violence from late 2007 was compared directly with the extremely violent 2006 and the first half of 2007. To look a bit further back, the level of violence after the success of the “surge” in late 2007, was roughly the same as the level of violence in Iraq in 2005.
When Barack Obama described the success of the “surge” as 'beyond our wildest dreams' on September 4 2008, it is important to emphasise that this was a tactical success that managed to reduce violence in Iraq. There was no Iraqi political breakthrough that would have led to a strategic success. The political limbo after the elections in 2010 showed that the new political system was far from functioning perfectly and it left public opinion in Iraq less secure about their belief in the new democratic system. When assessing if the “surge” succeeded in Iraq, you could also arguably debate the overall criterion for American success in Iraq. The question is if success is judged by the quite lofty ambitions the US administration had for Iraq before the invasion in 2003, or the more sober long-term aims Petraeus gave to congress in April 2008, which focused on preventing huge outbreaks of violence and making sure Iraq would not threaten her neighbours or be a base for Al Qaeda. 
When answering the question of why the “surge” in Iraq succeeded, I have argued that a large part of the answer is to be found in local factors that were specific to the conflict in Iraq at the time of the “surge”. The five causes for declining violence I have assessed in this essay are the Shiite victory in the civil war, the formation of “Sons of Iraq” groups, the US “surge” with new tactics and extra troops, the cease-fire of the Mahdi Army and the role of regional actors. I would argue that the interrelationship between these causes is central to explaining why violence was reduced in Iraq during the “surge”.
The numbers of “significant activities” in Iraq show that the formation of the “Sons of Iraq” led to violence in Iraq declining 2,5 times as fast as before, indicating the important role this played in reducing violence. Then again, it is very hard to tell if the “Sons of Iraq” movement would have become so big without the Shiite civil war victory and if it would have survived without the US “surge” to foster it. I also want to emphasise that the success of the “surge” was mainly a tactical success. Political problems continued to bring instability to Iraq after the “surge”, and there are still large-scale violent attacks taking place in Iraq today.
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Accessed 06/12-20012 at http://prospect.org/article/sunni-world
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Sky, Emma (2011), 'From Surge to Sovereignty', Foreign Affairs, Vol. 90, No. 2, pp. 117-127.
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 Kilcullen (2009), p. 120
 Biddle, Friedman & Shapiro (2012), p. 7
 Burke (2011), p. 269
 Biddle, Friedman & Shapiro (2012), p. 7
 Kilcullen (2009), p. 129.
 Timeline: Invasion, surge, withdrawal; U.S. forces in Iraq
 Burke (2011), p. 280
 Ucko (2008), p.346.
 Dodge (2006), p. 165
 Ibid, p. 162
 Aylwin-Foster (2005), p. 5
 Kilcullen (2009), p. 141.
 Burke (2011), p. 240
 Kilcullen (2009), p. 120.
 Rosen (2009), p.101.
 Ucko (2008), 357
 Ricks (2009), pp. 200-201
 Ricks (2009), p. 200
 Kilcullen (2009), p. 142-143
 Rosen (2009), p. 61
 Ucko (2008), p. 352
 Ibid, 352
 Ibid, 352
 Rosen (2009), p.104.
 Crider (2009), p. 83
 Biddle, Friedman & Shapiro (2012), p. 28
 Kilcullen (2009), p. 165
 Ucko (2008), p. 358.
 Lynch (2007)
 Ricks (2009), p. 207
 Gentile (2009), 10
 Biddle, Friedman & Shapiro (2012), pp. 30-31
 Ricks (2009), p. 200
 Rosen (2009), p. 227.
 Burke (2011), p. 267.
 Collier (2010), p. 89
 Gentile (2009), p. 11
 Biddle, Friedman & Shapiro (2012), p. 35
 Crider (2009), p. 84
 Biddle, Friedman & Shapiro (2012), p. 21
 Biddle, Friedman & Shapiro (2012), p. 21
 Burke (2011), p. 275.
 Kilcullen (2009), p. 177.
 Ucko (2008), p. 362
 Biddle, Friedman & Shapiro (2012), p. 25
 Burke (2011), p. 267.
 Biddle, Friedman & Shapiro (2012), pp. 17-18
 Rosen (2009), p. 235
 Kilcullen (2009), pp., 151-152
 Burke (2011), pp. 276-277
 Ibid, 277
 Biddle, Friedman & Shapiro (2012), p. 25 & 36.
 Burke (2011), p. 267
 Burke (2011), p. 272.
 Burke (2011), p. 272
 'Obama Says Iraq Surge Success Beyond `Wildest Dreams' (Update2)', http://www.bloomberg.com/apps/news?pid=newsarchive&sid=aM9XOyqf06lI, 6 December 2012
 Ricks (2009), p. 9
 Sky (2011), p. 9
 Burke (2011), p. 281.