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Iraq since the invasion: 20 years in SIPRI data

The Turkish restaurant, Iraqi protests 2019. Photo: Majed/Wikimedia
The Turkish restaurant, Iraqi protests 2019. Photo: Majed/Wikimedia

Twenty years ago this month, a multinational coalition led by the United States and the United Kingdom invaded Iraq. In the words of US President George W. Bush, the aim of the invasion was ‘to disarm Iraq of weapons of mass destruction, to end [Iraqi President] Saddam Hussein’s support for terrorism, and to free the Iraqi people’.

On 20 March 2003, a massive multinational coalition force invaded Iraq under Operation Iraqi Freedom. After three weeks of an intensive air and ground campaign, the Iraqi capital, Baghdad, fell, and with it Saddam’s Ba’athist regime. Shortly afterwards, the Coalition Provisional Authority decided to disband the Iraqi Army. No weapons of mass destruction were ever found.

Estimates of civilian casualties of the war vary, but are generally in the hundreds of thousands. Many more people have been injured or displaced since the invasion. A 2005 constitution set in place a system of parliamentary democracy, with formal power-sharing arrangements between the country’s main ethno-sectarian groups. The Iraqi state formally took over responsibility for security in 2009, after which the coalition troop presence was gradually reduced from around 131 000 in 2009 to zero by the end of 2011.

Nevertheless, the new Iraqi state remained heavily dependent on foreign assistance, including both financial aid and supplies of military equipment, for many years. Iraq and its people have had to contend with long-running violent insurgencies and ethno-sectarian violence. In 2014 the Islamic State (IS) armed group was able to seize and control large swathes of the country by force before finally being defeated in 2017. Today, Iraq remains politically unstable and fragile.

This SIPRI Topical Backgrounder presents data for Iraq drawn from four SIPRI databases data covering the period since the invasion, and what it reveals about developments in the country since the invasion.

Military expenditure

Military expenditure

SIPRI’s estimates for Iraqi military expenditure are highly uncertain. They are based on regular financial reports published by the Iraqi government, with figures for the Iraqi Ministry of Defence. However, these figures do not cover all the military expenditure that would fall within SIPRI’s definition.

One ‘known unknown’ is expenditure on paramilitary forces, which is not included in the financial reports. This could be as large as the Ministry of Defence budget, given Iraq’s fragile security situation. As SIPRI has not identified a reliable data source for spending on these paramilitary forces, the SIPRI data certainly understates the full extent of Iraq’s military expenditure. Another issue is comprehensiveness. Budgets often lack a figure under the item ‘investments’, and when it is present it varies considerably year on year. Finally, a great deal of spending on security in Iraq was funded by external aid.

With these caveats in mind, it is still possible to observe some developments in the publicly available data over the 20 years following the invasion of Iraq. A slight upward trend in military spending starts in 2007, coinciding with a major offensive campaign conducted jointly with US troops against al-Qaeda forces.

The increase in military spending becomes steeper in the early 2010s, as US troops were drawn down and the US military presence in the country officially ended in December 2011. Sectarian violence escalated in this period.

This already fragile security situation was further worsened by the rise of the Islamic State group. In 2014, IS began to take control of large swathes of Iraq. The Iraqi government responded with a large-scale military operation, aided by US-led multinational troops and airstrikes. Military spending peaks in 2015, when the Iraqi army launched a major offensive in Tikrit. Iraq declared victory against IS in 2017, after recapturing the city of Mosul.

After 2020, military spending falls both in absolute terms and as a share of GDP. This coincides with the Covid-19 pandemic and a period of high volatility in the price of oil, a critical revenue stream for Iraq .

Arms imports

Arms imports by supplier

Soon after the removal of Saddam Hussein’s regime in 2003, Iraq began—with large-scale assistance from the USA—rebuilding armed forces that would be suitable for fighting the armed groups currently operating in the country. For this purpose, Iraq received large numbers of primarily lighter types of arms and support equipment, for example, over 10 000 light armoured vehicles and over 100 transport helicopters, along with hundreds of thousands of small arms and light weapons (SALW). Many SALW were supplied by the USA and European states. The major arms came mainly from the USA. In the early years after the invasion particularly, imports of Russian arms to Iraq were often paid for by the USA.

Arms imports by type of arms

From about 2011—by which point most US forces had withdrawn and the country—to 2018, Iraq sought to establish more fully fledged armed forces and thus bought heavier and more advanced equipment from a broader group of suppliers. This included tanks and combat aircraft from the USA; air-defence systems and combat helicopters from Russia; and combat aircraft from South Korea.

There was a renewed spike in military aid from the USA in 2014–16 in response to the rise of IS. Many more light weapons and armoured vehicles were delivered to aid Iraq in fighting IS and to replace weapons captured or destroyed by the group.

With IS largely defeated in the country and Iraqi armed forces much better equipped for internal security and territorial defence, Iraqi arms imports started to decrease in 2018. The Iraqi government has in recent years announced several plans for further substantial arms acquisitions, although the status of these projects remains unclear.

Controls on arms transfers and small arms and light weapons

In the two decades since the invasion Iraq has seen high rates of diversion of arms and ammunition. The collapse of the Iraqi state after the invasion led to large-scale looting of national stockpiles. In such a context some diversion was probably inevitable. However, the scale and speed at which it happened highlighted major shortcomings in physical security and stockpile management (PSSM). This, in combination with the government’s pre-invasion arming of militia forces, led to an estimated 4.2 million small arms and light weapons falling into the hands of  civilians or non-state armed groups, helping to fuel the internal conflicts that broke out after the invasion. Many weapons also crossed the border into neighbouring countries.

Later on, in 2014, IS captured significant amounts of weapons from Iraqi security forces. More than 10 per cent of weapons recovered from IS by inspection teams of the organization Conflict Armament Research in 2014–17 originally came from Iraqi national stockpiles.

Table 1

The Iraqi state has made concerted efforts to improve the situation and to address diversion and related shortcomings in its arms-transfer and SALW control systems. SIPRI’s database of cooperation and assistance activities relevant to the 2013 Arms Trade Treaty includes 25 entries that involved Iraq in 2012–22. These activities focused mainly on inventory and stockpile management for SALW, tracing the origin of illicit SALW and preventing the diversion of SALW and conventional arms. They included, for example, PSSM training as well as baseline assessments of weapons and ammunition management.

Among other things, Iraq has frequently requested assistance in the past decade through its reports under the United Nations Programme of Action on SALW (UNPOA), mostly to improve its laws and regulations. Under the framework of UN Security Council Resolution 1540 (2004)—which requires states to prevent non-state actors from obtaining nuclear, chemical or biological weapons or their means of delivery—Iraq has requested support in adopting and using the European Union military list.

Multilateral Peace operations in Iraq

Personnel deployed to multilateral peace operations in Iraq

Iraq has hosted several multilateral peace operations since 2003. The first of these, the UN Assistance Mission for Iraq (UNAMI), was deployed in August 2003 and remains active. UNAMI is a UN special political mission that was established by UN Security Council Resolution 1500 on 14 August 2003. UNAMI has among other things facilitated national dialogue and consensus building on the political transition process in post-war Iraq. It currently focuses on advising, supporting, and assisting the Iraqi government on a broad range of issues including inclusive political dialogue, reconciliation efforts, human rights and humanitarian aid delivery. Personnel deployments to UNAMI peaked at 754 in 2007 and have stayed at 500–600 for most of its lifespan, with a roughly even split between civilian and military personnel.

The EU has conducted two small civilian peace operations in Iraq. The EU Integrated Rule of Law Mission in Iraq (EUJUST LEX Iraq) ran from 2005 to 2013 and focused on training and advice in the rule of law and criminal justice sectors. The EU Advisory Mission in Iraq (EUAM Iraq), established in 2017, provides training and advice and in the civilian security sector.

The North Atlantic Treaty Organization (NATO) has also conducted two small non-combat military training missions focused on the development of Iraqi military security forces and institutions. The NATO Training Mission–Iraq (NTM-I) ran from 2004 to 2011. The NATO Mission in Iraq was established in 2018 and is still active.

Personnel deployed to the Multinational Force in Iraq

For much of the time, the relatively small-sized missions described above have worked in the shadow of much more significant international military operations led by the United States, fighting first against several various Iraqi armed insurgent groups (2003–2011) and later against IS (2014–21). The US-led Multinational Force in Iraq (MNF-I) was initially also considered a multilateral peace operation by SIPRI. UN Security Council Resolution 1511 on 16 October 2003 authorized MNF-I to, among other things, contribute to the maintenance of security and stability in Iraq. However, SIPRI excluded MNF-I from its annual list of multilateral peace operations as of 2006 because the mission’s focus had largely shifted to counter-insurgency. MNF-I comprised more than 180 000 troops at its peak in 2005.


To commemorate the upcoming 20th anniversary of the invasion of Iraq on 20 March, SIPRI has prepared this Topical Backgrounder along with an Interactive chronology of security developments in Iraq spanning from 2002 to 2021. These materials are components of a larger collection of new materials that SIPRI is creating to commemorate the anniversary.


Lauriane Héau is a Researcher in the Dual-Use and Arms Trade Control Programme at SIPRI.
Dr Diego Lopes da Silva is a Senior Researcher with the SIPRI Military Expenditure and Arms Production Programme.
Lorenzo Scarazzato is a Research Assistant with the SIPRI Military Expenditure and Arms Production Programme.
Timo Smit is a Senior Researcher in the SIPRI Peace Operations and Conflict Management Programme.
Pieter D. Wezeman is a Senior Researcher in the SIPRI Arms Transfers Programme.