The War against the Islamic State was a global effort to destroy the Islamic State terrorist organization and purported caliphate that began in 2014 in response to the group's sweeping territorial gains in Syria and Iraq and its universally condemned human rights violations. IS' expansion into Africa and Asia resulted in smaller states mounting their own local interventions against IS, including in Nigeria and Libya. IS controlled around 40% of Iraq at its peak in mid-2014 and 50% of Syria by May 2015, but it was defeated in Libya and Iraq in December 2017 and in Syria in March 2019, depriving it of territorial control in those regions and reducing it to an insurgency. However, over 10,000 IS fighters remained in Syria and Iraq by August 2020, while IS continued to inspire Islamist lone-wolf and organized terror attacks in enemy countries and controlled limited territory in Africa.
History[]
The Islamic State of Iraq (ISI) was proclaimed by the al-Qaeda (AQ)-affiliated Mujahideen Shura Council (MSC) on 13 and 15 October 2006, claiming territorial control over Iraq's Sunni Arab-majority regions. In May 2010, Ibrahim al-Badri ("Abu Bakr al-Baghdadi") became leader of ISI following the deaths of Abu Omar al-Baghdadi and Abu Ayyub al-Masri, and, by the time of the US withdrawal from Iraq in late 2011, his group had up to 2,500 fighters. The start of the Syrian Civil War in 2011 led to Baghdadi and AQ central command authorizing the establishment of the al-Nusra Front as a Syrian offshoot of al-Qaeda, aiming to overthrow Bashar al-Assad's secular dictatorship and establish an Islamic state there. On 8 April 2013, however, Baghdadi proclaimed the creation of the Islamic State of Iraq and the Levant (ISIL), unilaterally declaring the merger of ISI and al-Nusra. al-Nusra leader Abu Mohammad al-Julani rejected the merger, causing some al-Nusra members (particularly foreign fighters) to follow Baghdadi's edict and join ISIL. ISIL rejected al-Qaeda leader Ayman al-Zawahiri's mediation attempts and publicly denounced Zawahiri on 15 June 2013, effectively splitting off from al-Qaeda and resulting in violent conflict in January 2014. ISIL took control of the Nusra-held city of Raqqa on 13 January 2014 and established its capital in that city, initiating a series of offensives that conquered much of Syria. On 4 June 2014, ISIL launched a major offensive in northern Iraq that captured the cities of Mosul, Baiji, Tal Afar, and Tikrit, and most of western and northern Iraq fell to the jihadists. On 29 June 2014, Baghdadi proclaimed the creation of the Islamic State, a caliphate aiming to rule the entire Muslim world. Baghdadi would henceforth call himself "Caliph Ibrahim," and he called on Muslims across the world to swear allegiance. As regional terror groups like Boko Haram in West Africa, Ansar Bait al-Maqdis in Egypt, the Caucasus Emirate in the North Caucasus, Abu Sayyaf in the Philippines, and factions of the Taliban and Al-Qaeda in the Arabian Peninsula and in the Islamic Maghreb swore allegiance to the caliphate, the Caliph proclaimed the formation of new "provinces" (wilayah), which would be funded via illegal oil sales and donations from wealthy Gulf state donors.
On 13 June 2014, NATO unanimously condemned IS' "barbaric act" in Iraq, and, on 5 September 2014, the United States, Australia, Canada, Denmark, France, Germany, Italy, Turkey, and the United Kingdom agreed to fight against ISIL militarily and financially. In September 2014, Jordan and Saudi Arabia joined NATO in waging a joint aerial campaign against IS bases across Iraq and Syria. On 17 October 2014, the USA formally established the Combined Joint Task Force - Operation Inherent Resolve (CJTF-OIR) coalition to formalize their intervention against the Islamic State.
As nations across the world joined the anti-IS coalition, IS responded with a propaganda campaign calling on their agents and sympathizers across the world to carry out terror attacks. IS also released several videos depicting the executions of foreign hostages. The November 2015 Paris attacks persuaded the French government to step up its bombing campaign in Syria and the British Parliament to authorize airstrikes in Syria on 2 December 2015. Canada participated in airstrikes from November 2014 to February 2016, while the Netherlands did so until December 2018. Morocco contributed planes to an Emirati bombing campaign until February 2015.
In addition to the Western-Gulf State coalition, the Iranian and Russian-backed "Axis of Resistance" - which included Syria, Hamas-run Gaza, Shia paramilitaries in Iraq, Hezbollah in Lebanon, and the Houthis in Yemen - waged their own campaign against ISIL. On 21 June 2014, Iran joined the air war against IS, sending several Su-25 aircraft to Iraq. Quds Force and Hezbollah personnel were dispatched to help lead the Shia Popular Mobilization Units and Syrian Arab Army in battle, just as US advisors had been sent to aid the Syrian Democratic Forces in Syria and the Peshmerga in Iraqi Kurdistan. In September 2015, the Russian Air Force began a military intervention in Syria that destroyed both IS and moderate rebel bases. Talks between the USA and Russia to coordinate their airstrikes fell through in mid-2016.
The combination of Coalition and Russian airstrikes and on-the-ground advisory support for IS' regional enemies gradually forced the caliphate's fighters back. Mosul was retaken by Iraqi government, Iraqi Kurdish, and Shia paramilitary forces in July 2017, while the Kurdish-led Syrian Democratic Forces liberated Raqqa on 20 October 2017. By December 2017, ISIL was deprived of territorial control in both Iraq and in Libya, and IS was defeated in Syria at the Battle of Baghuz Fawqani on 23 March 2019. Baghdadi was killed in a US special forces raid in northern Syria in October 2019, and a string of successive "caliphs" were hunted down and killed by the US and its allies over the next several years. In West Africa, a regional coalition nearly destroyed Boko Haram, while, in the Philippines, the major terror groups disbanded in 2024. Though IS established control over much of Cabo Delgado Province in northern Mozambique by 2019, a Mozambican and Rwandan counteroffensive recaptured several towns and cities. IS continued to fight against the Taliban in Afghanistan and possessed significant territories in the Sahel by 2024, and the West's perceived inability to defeat Islamist insurgents in West Africa led to several pro-Russian military regimes seizing power and inviting Wagner Group mercenaries to aid their militaries.
As a result of the international campaign against IS, over 80,000 militants were killed, as were over 16,000 Iraqi soldiers, 11,000 Rojavan Kurds, 8,000 Syrian government soldiers, 3,378 Syrian rebels, 1,500 Iraqi Kurds, 700 Egyptians, 100 Chadians, 76 Turks, 48 Nigerians, 35 Iranians, 28 Russians, 9 Nigeriens, 6 Americans, 6 Cameroonians, 3 Saudis, 1 Canadian, 2 Frenchmen, 3 Britons, and 1 Jordanian. Over 13,500 Iraqi civilians and 6,000 Syrian civilians were killed by IS, while between 1,417 and 13,190 civilians in Iraq and Syria were killed in Coalition airstrikes and up to 6,085 Syrian civilians killed by Russia.
Despite IS' territorial elimination in the Middle East, it continued to recruit among Sunni Arab tribes who chafed under Kurdish or Shia rule in Syria and Iraq, and thousands of imprisoned IS members in both countries posed a serious security threat should they escape or be allowed to return to their home countries. In addition, lone-wolf attacks continued even after the demise of the caliphate, as individuals were radicalized on the internet and made videotaped pledges of allegiance before cultivating their own plans.