Many states began to intervene against the Islamic State (IS), in both the Syrian civil war and the War in Iraq (2013–2017), in response to its rapid territorial gains from its 2014 invasion of Iraq, widely condemned executions, human rights abuses and the fear of further spillovers of the Syrian civil war. In later years, there were also minor interventions by some states against IS-affiliated groups in Nigeria and Libya. All these efforts significantly degraded the Islamic State's capabilities by around 2019–2020. While moderate fighting continues in Syria, as of 2026, IS has been contained to a small area and force capability. In mid-June 2014, Iran, according to American and British information, started flying drones over Iraq, and Iranian soldiers were in Iraq fighting IS. Simultaneously, the US ordered a small number of troops to Iraq and started flying crewed aircraft over Iraq. In July 2014, Iran sent Sukhoi Su-25 aircraft to Iraq, and Hezbollah purportedly sent trainers and advisers to Iraq in order to help Shia militias to monitor IS's movements. In August 2014, the US and Iran separately began a campaign of airstrikes on IS targets in Iraq. Since then, fourteen countries in a US-led coalition have also executed airstrikes on IS in Iraq and in Syria. Starting from September 2014, the US began closely co-operating with Saudi Arabia and Jordan to wage a co-ordinated aerial bombing campaign against IS targets across Iraq and Syria. In September 2015, Russian forces launched their military intervention in Syria to support their ally, Bashar al-Assad, in the fight against the Islamic State. Although Moscow officially portrayed its intervention as an anti-IS campaign and publicly declared support for the "patriotic Syrian opposition", the vast majority of its bombings were focused on destroying bases of the Syrian opposition militias of the Free Syrian Army (FSA) and Southern Front. On the other hand, the United States and its Western allies have been opposed to the former Ba'athist regime for its purported state-sponsorship of terrorism, violent repression of the Syrian revolution and extensive use of chemical weapons. The US-led coalition trained, equipped and supported secular Free Syrian and Kurdish militias opposed to the Assad government during its anti-IS campaign. In the months following the beginning of both air campaigns, IS began to lose ground in both Iraq and Syria. Civilian deaths from airstrikes began to mount in 2015 and 2016. In mid-2016, the US and Russia planned to begin coordinating their airstrikes; however, this coordination did not materialize. As of December 2017, IS was estimated to control no territory in Iraq, and 5% of Syrian territory, after prolonged actions. On 9 December 2017, Iraq declared victory in the fight against ISIL and stated that the War in Iraq was over. On 23 March 2019, IS was defeated territorially in Syria after losing the Battle of Baghuz Fawqani, after which the group was forced into an insurgency. IS's leader, Abu Bakr al-Baghdadi, died during a US special operations raid in northern Syria in October 2019 and was succeeded by Abu Ibrahim al-Hashimi al-Qurashi. In August 2020, over 10,000 IS fighters were estimated to remain in Syria and Iraq, mainly as sleeper cells.
International coalitions against the Islamic State
=== US-led coalitions === On the margins of the 4/5 September 2014 NATO summit in Wales, on 5 September 2014, U.S. Secretary of State John Kerry invited Ministers of Australia, Canada, Denmark, France, Germany, Italy, Turkey and the United Kingdom, for a separate meeting in which he pressed them to support the fight against ISIL militarily and financially. Those nine countries agreed to do so by supporting anti-ISIL forces in Iraq and Syria with supplies and air support, according to a statement that day from Kerry and U.S. Secretary of Defense Hagel. In September 2014, Jordanian and Saudi Air Forces began their co-ordination with United States to wage a joint aerial bombing campaign against IS bases in its territories across Iraq and Syria.
On 17 October 2014, the Department of Defense formally established Combined Joint Task Force – Operation Inherent Resolve (CJTF-OIR)—"in order to formalize ongoing military actions against the rising threat posed by ISIS in Iraq and Syria." On 3 December 2014, at the NATO headquarters in Brussels, diplomats and foreign ministers from 59 countries gathered to plot a way forward against the threat of ISIL. U.S. Secretary of State John Kerry told the gathering, that "defeating the ideology, the funding, the recruitment" of Daesh (ISIL) must be the primary focus of their discussion, more important than airstrikes and other military action. The countries represented on 3 December were: the nine countries of the above-mentioned 5 September coalition in Wales (see above); the extra 18 countries of the 15 September France-led coalition in Paris (see below) except for China and Russia; and 33 additional countries: Albania, Austria, Bosnia-Herzegovina, Bulgaria, Croatia, Cyprus, Estonia, Finland, Georgia, Greece, Hungary, Israel, Iceland, Ireland, Kosovo, Latvia, Lithuania, Luxembourg, Macedonia, Moldova, Montenegro, Morocco, New Zealand, Portugal, South Korea, Romania, Serbia, Singapore, Slovakia, Slovenia, Somalia, Sweden, Taiwan and Ukraine. They styled themselves as the Global Coalition to Counter the Islamic State of Iraq and the Levant (ISIL), and agreed to a strategy that included:
exposing ISIL's true nature; cutting off ISIL's financing and funding; supporting military operations.
France-led coalition
On 15 September 2014, at the 'International Conference on Peace and Security in Iraq' hosted by the French President François Hollande in Paris, 26 countries were represented: the countries of a US-led coalition that on 5 September in Wales (see above) had agreed on a coalition against ISIL except Australia and Poland, and furthermore Bahrain, Egypt, Iraq, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, United Arab Emirates, Belgium, China, Czech Republic, Japan, the Netherlands, Norway, Russia and Spain. They committed themselves to supporting the Iraqi government with military assistance in its fight against ISIL, and they reaffirmed their commitment to UNSC Resolution 2170 of 15 August (condemning all trade with ISIL and urging to prevent all financial donations and all payments of ransoms to ISIL), so reported the French government. In retaliation for the November 2015 Paris attacks, the French Air Force significantly intensified airstrikes against ISIL targets in Syria, hitting among other targets the Syrian city of Raqqa, the de facto capital of ISIL. The French Navy deployed the aircraft carrier Charles de Gaulle with eighteen Rafale, eight Mirage 2000, two E-2 Hawkeye and 4 helicopters. The aircraft carrier travelled with the frigate Chevalier Paul and HMS Kent.
Russia-led coalition
At the end of September 2015, Russia, Iraq, Iran and Syria set up a 'joint information center' in Baghdad to gather, process and analyse intelligence regarding ISIL and operations near the Syria-Iraq border. On 30 September 2015, Russia began its air campaign on the side and in support of the Syrian government. Russia was also reported to have reached agreements on co-ordination of operations in Syria with Jordan and Israel. On 14 March 2016, Russian President Vladimir Putin announced a partial withdrawal from Syrian territory, citing the success of the ongoing ceasefire and greater security of the Syrian government. On 10 December 2017 Vladimir Putin ordered a similar withdrawal of Russian forces from Syria, stating that a complete withdrawal would be dependent on the ongoing situation.
Muslim states' coalition
On 14 December 2015, Saudi Deputy Crown Prince and Defense Minister Mohammed bin Salman Al Saud announced that 34 countries would join in the fight against Muslim extremism, which he called a "disease." Based out of Riyadh, Saudi Arabia, the coalition includes Bahrain, Bangladesh, Benin, Chad, Comoros, Côte d'Ivoire, Djibouti, Egypt, Gabon, Guinea, Jordan, Kuwait, Lebanon, Libya, Maldives, Mali, Malaysia, Morocco, Mauritania, Niger, Nigeria, Pakistan, Palestine, Qatar, Saudi Arabia, Senegal, Sierra Leone, Somalia, Sudan, Turkey, Togo, Tunisia, the United Arab Emirates and Yemen.
Syria
US-led intervention in Syria
Hostage rescue attempt
On 4 July 2014, the U.S. bombed the "Osama bin Laden" ISIL military base in the village of Uqayrishah, Syria. Two dozen American Delta Force operators then touched down in an effort to rescue hostages, including James Foley. The effort failed, with the hostages having been moved to another location days prior. In a series of videos, Foley, Steven Joel Sotloff, and several more hostages were murdered.
==== Aerial surveillance ==== On 26 August 2014, the U.S. began sending surveillance flights, including drones, into Syria to gather intelligence. The Syrian Arab Republic was not asked for permission. On 28 August, speaking about combating ISIL in Syria, President Obama said "we don't have a strategy yet." The British Royal Air Force has been operating over Syria in a surveillance role since 21 October 2014, making the UK the first Western country other than the United States to operate in both Iraq and Syria simultaneously.
Arming and training rebels
At the direction of President Obama, the U.S. Central Intelligence Agency played an active role since the early stages of the Syrian Civil War. The U.S. initially supplied the vetted militias of the Free Syrian Army with non-lethal aid but soon escalated to providing training, money, and intelligence to the rebel commanders. In June 2014, Obama requested Congressional authorization of $0.5 billion to train, arm and support vetted Free Syrian militias as a counter-force against both Assad regime and IS.
On 17 September 2014, the House of Representatives voted to authorize the proposal to train and arm pro-Western Free Syrian militias, with the objective of training 5,000–10,000 troops. Syrian opposition's National Revolutionary Coalition welcomed Obama's announcement of extending the anti-IS bombing campaign into Syria, stating: "The Syrian Coalition ... stands ready and willing to partner with the international community not only to defeat ISIS but also rid the Syrian people of the tyranny of the Assad regime" The United Kingdom announced in March 2015 that it would send 75 military personnel to help train Western-vetted Free Syrian militias in the use of small arms, infantry tactics and basic medical skills. The training was supposed to take place in Turkey as part of the U.S.-led effort. According to the United States Department of Defense, Saudi Arabia proposed that they could provide training to Syrian rebels so they could return to Syria and battle ISIL. The effort to train a large force of Syrian rebels from anti-Assad factions to fight ISIL ultimately failed, with only 54 fighters in Division 30 trained and many captured, killed or not fighting.
Multi-national airstrikes
U.S. President Barack Obama announced on 10 September 2014 that he would begin to extend aerial campaign to Syria with or without congressional approval. Many Senators were opposed to Obama's policy of unilateral intervention, without requesting a congressional mandate. While Obama acknowledged the broad consensus in the US intelligence community that IS were not a "current threat" to United States, he claimed that IS posed a future danger to the US, citing the anti-American rhetoric of IS leadership. Pentagon leadership preferred a greater involvement of US boots to combat IS, but this was rejected by Obama, who instead favoured working with Iraqi Ground forces, Peshmerga and Syrian opposition militias. Starting on 22 September 2014, the U.S., Bahrain, Jordan, Qatar, Saudi Arabia, and the United Arab Emirates began numerous large-scale airstrikes against ISIL targets in Syria with fighters, bombers, and sea-based Tomahawk cruise missiles. The strikes were the largest aerial bombing operations launched against IS targets since US launched its military campaign against IS in August 2014. Hadi al-Bahra, President of the National Coalition of Syrian Revolutionary and Opposition Forces, stated that the strikes were "necessary" to aid the Syrian people's fight against ISIL and urged the Coalition Forces to steer clear of civilian casualties. United States has ruled out any co-operation with Bashar al-Assad in the fight against IS, instead issuing warnings to the Syrian military to disengage from Coalition aircraft. State Department spokesperson Jen Psaki stated that no notifications had been issued to Assad regime with regard to US operations in Syrian airspace. Additionally, on the first night, the U.S. forces also launched eight cruise missile strikes against the al-Qaeda-affiliated Khorasan. Many airstrikes were focused against IS command & control facilities, training camps, supply depots, military facilities, etc. in and around Raqqa. Strikes continue to take place in Syria daily. In early November early December 2014, the U.S. launched additional airstrikes against the same group. In November 2014, Morocco sent 3 F-16s to be deployed in UAE, to fight ISIL in Iraq and Syria under U.S.-led operations. On 24 December 2014, ISIL shot down a Jordanian fighter jet over Syria and captured its pilot, Jordanian air force lieutenant Muath Al-Kasasbeh. Al-Kasabeh was offered in exchange for captured ISIL fighters. Jordan offered to make the exchange, but demanded "proof of life" first. However, Al-Kasabeh had already been executed by immolation. When video of the pilot's execution was released, a moratorium on executions in Jordan was lifted and the Al-Qaida operatives, Sajida al-Rishawi and Ziad al-Karbouli were executed. On 21 August 2015, three ISIL fighters, two with UK nationality, were targeted and killed in Raqqa, Syria by a British Royal Air Force MQ-9 Reaper strike. Prime Minister David Cameron gave a statement to Parliament that one of the British nationals targeted had been plotting attacks in the United Kingdom. Another British national was killed in a separate air strike by US forces in Raqqa on 24 August.
In October and November 2015, the U.S. intensified its airstrikes on ISIL-held oil facilities in an operation named "Tidal Wave II", after the World War II campaign against Axis oil targets in Romania. The U.S. strategy aimed "to knock out specific installations for six months to a year" by focusing on facilities near Deir el-Zour. The Omar oil field, which produced 30,000 barrels of oil per day and $1.7 million to $5.1 million in revenue per month at full capacity, was hit on 21 October, reducing it to roughly a third of its capacity. French aircraft also participated in the strikes. On 16 November 2015, a U.S. Operation Tidal Wave II sortie destroyed 116 ISIL fuel tankers clustered near Abu Kamal, a city on the Syrian border with Iraq. Four A-10 Thunderbolt IIs and two AC-130 Spectre gunships participated in the raid. Before attacking the trucks the planes conducted several low-level, 'show of force' passes. On 2 December 2015, the Parliament of the United Kingdom voted in favour (397 to 223) to authorise air strikes in Syria. Within hours, RAF Tornado jets carried out their first air strikes, targeting the Omar oil fields in eastern Syria, which were under ISIL control. Tornado GR-4 jets were used for surveillance and a further six Typhoons left RAF Lossiemouth, Scotland to join forces at RAF Akrotiri, Cyprus. On 4 December 2015 Germany intervened in reaction to the November 2015 Paris attacks by sending the frigate Augsburg (F213) and Panavia Tornado reconnaissance aircraft to the region. The Augsburg concluded its first deployment in March 2016, redeploying in September and concluding its mission on 14 November 2016. On 29 January 2016, the Netherlands announced its intent on expanding its airstrike operations to Syria. In June 2016, Omar Mateen, the attacker from the Pulse nightclub shooting pledged allegiance to the Islamic State and gave U.S. collaboration with Russia in airstrikes against I.S. as a reason for the attack.
Russian intervention
On 11 September 2015, a Syrian military source made mention of Russian troops present in Syria to help the Syrian government in its fight against ISIL, as part of Operation Rescue. On 17 September, Syrian warplanes carried out a wave of airstrikes in the ISIL-held city of Raqqa with Russian weapons supplied by Russian Armed Forces. On 20 November, Russia claimed to have killed over 600 terrorists using cruise missiles in one mission.
Turkish intervention
ISIL is suspected of involvement in or responsibility for terrorist attacks in Turkey in May 2013 in Reyhanlı and March 2014 on Turkish police, kidnapping 49 Turkish diplomats in June 2014, the 5 June 2015 Diyarbakır rally bombing and 20 July 2015 Suruç bombing which killed 32 young activists. Until July 2015, the Turkish government attacked ISIL only once, in January 2014. In September 2014 Turkey joined a US-led coalition 'to fight ISIL'.
==== July 2015 special forces operation ==== On 23 July 2015, according to various Turkish news outlets, 60 elite Special Forces (ÖKK) operatives reportedly infiltrated Elbeyli-Ayyase village, 9 kilometers from the Syria-Turkey border in Syria, and took it back from ISIL militants. Turkish tanks shelled the village the same day of the ground operation. The operation reportedly lasted over an hour and killed over 100 ISIL militants, according to reports. The Turkish General Staff neither confirmed nor denied the special forces foray but did confirm shelling the village. The same day, Turkey allowed the United States to use İncirlik and Diyarbakır air bases in southern Turkey for airstrikes on ISIL in Syria, and after an alleged ISIL attack on a Turkish border outpost in Kilis Province killing one Turkish soldier, the Turkish army shelled ISIL militants in Syria, killing one militant and destroying several ISIL vehicles. On 24 July, an anonymous report appeared on a Turkish newspaper website stating that the United States had agreed with Turkey on a 'partial no-fly zone' in northern Syria. On 24 and 25 July the Turkish Air Force launched a military operation entitled 'Operation Martyr Yalçın' against both ISIL in Syria and the Kurdistan Workers' Party (PKK) in Iraq, deploying at least 70 F-16 fighter jets.
Iranian intervention
As the conflict intensified after the rise of IS in 2014 and the subsequent deterioration of the regime's control, Iran dramatically escalated its involvement. By mid-2014, Iran began dispatching members of its elite Islamic Revolutionary Guard Corps (IRGC), including its Quds Force, along with other Iranian armed-forces personnel. At the same time, Iran organized, trained and deployed a wide array of Shiite militias: foreign volunteers, Iraqi militias that Tehran already supported, and locally raised Syrian pro-regime militias. At the height of its intervention from 2015-2018, estimates suggest that Iran had placed as many as 10,000 IRGC personnel and a substantial number of Iranian-led foreign militias on the ground in Syria. Iranian forces backed by drones, ballistic-missiles, and air-power carried out hundreds of strikes against IS targets. By October 2018, Iranian drones alone had reportedly launched more than 700 strikes on Islamic State forces. By 2025 more than 2,100 Iranian soldiers had been killed in Syria. The collapse of the regime's stability in late 2024 then significantly undermined Iran's influence in Syria.
Kurdish-led war
Democratic Autonomous Administration of North and East Syria is a major theater in the war against the Islamic State in Syria. During the Syrian Civil War, Kurdish forces led by the People's Protection Units (YPG) took control of Northern Syria and launched campaigns to take control of the Islamist-controlled areas. The Syrian Democratic Forces went on to take substantial territory from the Islamic State and played a major role in the liberation of Raqqa and the battle for Deir Ezzor, ending Islamic State rule in Syria.
Hezbollah intervention
The Lebanese Shiite militia and political-military group Hezbollah intervened in Syria early in the civil war, initially as military advisers and fighters sent to support the regime of Assad, but over time their role grew both in scale and strategic importance. Starting around 2012-2013, Hezbollah began deploying operatives to Syria, initially to assist in key regions like Homs, the Qusayr area, and around Damascus; including to defend Shi'a holy sites and minority communities. Hezbollah's involvement was not only military: it helped organize, train, and lead many of the pro-regime militias later subsumed under broader entities like the National Defence Forces (NDF). Hezbollah's intervention in Syria effectively ended with the fall of the Assad regime in December 2024. The group withdrew its fighters, and clashes began between the new Syrian transitional government and Hezbollah along the Lebanese-Syrian border.
Lebanon
In 2014, during the Syrian Civil War, Lebanon clashed against ISIL and other Jihadist insurgents present in the north of the country near the border with Syria. In June 2015, Hezbollah leader Hassan Nasrallah claimed that ISIL and Nusra had taken a foothold in Lebanon and that fierce battles were raging between them and Hezbollah, as well as each other.
Egypt
The Sinai insurgency began during the height of the 2011 Egyptian revolution when Egyptian President Hosni Mubarak was overthrown and a jihadist group called the Ansar Bait al-Maqdis (ABM) launched attacks against Egyptian security forces and civilians in the Sinai. Sometimes, the group conducted cross-border attacks against Israel as well. After another Egyptian president, President Mohamed Morsi, was overthrown in 2013, the ABM intensified its attacks against the Egyptian forces and governmental figures.
=== 2014 Islamic State rebranding === In November 2014, the ABM swore allegiance to the Islamic State and its then-leader, Abu Bakr al-Baghdadi. After making the commitment, the group changed its name to Islamic State – Sinai Province (IS-SP) and gained recognition as an affiliate of the ISIS, thus Egypt's involvement against the Islamic State became explicit. In 2015, the United States increased military aid to Egypt after lifting its suspension due to the 2013 coup. This included help with counterterrorism, sharing intelligence, and providing military equipment to fight Sinai-linked militants. Israel also permitted Egypt to exceed the quantity of troops and heavy equipment Egypt could deploy in the Sinai than allowed under the 1979 Egypt–Israel peace treaty. Israel also shared reconnaissance intelligence and sometimes performed airstrikes in the Sinai with Egyptian permission.
Sinai operations and clashes
During this period, the Egyptian Armed Forces significantly expanded its operations by demolishing suspected terrorist-controlled buildings and underground smuggling caves connecting Egypt and Gaza, establishing buffer zones near the borders of Gaza, implementing strict curfews in the Sinai, and turning to the scorched earth strategy. However, the Egyptian Security Forces were subsequently accused of war crimes, mainly by Human Rights Watch (HRW), due to excessive force causing civilian casualties and widespread displacement.
