Many states began to intervene against the Islamic State, 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, universally 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 2025, 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, according to Reuters, Iranian soldiers were in Iraq fighting IS. Simultaneously, the United States ordered a small number of troops to Iraq and started flying crewed aircraft over Iraq. In July 2014, according to the International Institute for Strategic Studies, 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, United States began closely co-operating with Saudi Arabia and Jordan to wage a co-ordinated aerial bombing campaign against IS targets across Iraq and Syria.
