How was Isis defeated?

The fight to defeat the caliphate brought together the bitterest of enemies, and cost tens of thousands of lives.

By the end, the terror group could count among its battlefield opponents two military superpowers in the US and Russia, along with the Syrian army, the Syrian armed opposition, the Kurdish-led Syrian Democratic Forces, the Kurdish Peshmerga, the Kurdistan Workers’ Party (PKK) the Iraqi army, a number of Iraqi Shia militias, Turkey and a global coalition of some 70 countries.

The battle was not always coordinated between these powers, but it is a sign of the brutality of Isis that they all found common cause to fight it.

In 2014, the group carried out one of its worst atrocities when it overran the town of Sinjar in northern Iraq. The town and the surrounding area is the traditional homeland of people from the Yazidi faith, whom Isis considers heretics. Isis fighters slaughtered thousands of civilians and took thousands of women as sex slaves. The UN would later categorise the attacks as a genocide.

That terrible crime, and the threat it posed to other areas of Iraq, prompted the US to intervene against Isis. In August 2014, as thousands of Yazidi civilians were surrounded by Isis fighters, the US launched the first airstrikes against the group.

It would be the first action in a long US-led coalition involvement that would prove decisive in defeating the Isis caliphate. Over the next few years, thousands of coalition airstrikes — most the vast majority of which were carried out by the US — would clear the path for local forces on the ground in Iraq and Syria to recapture ground from Isis. The coalition carried out more than 30,000 airstrikes across both countries. But while they were extremely effective, this tactic left a trail of destruction. The cities of Mosul and Raqqa, and many others, still lie in ruins.