Data on the foreign nationals who left their home country to join the caliphate.
Since 2013, over 50,000 foreign affiliates or foreign fighters travelled to Iraq and Syria to join Islamic State of Iraq and the Levant (ISIL) from at least 83 countries.
At the height of the caliphate in late 2014, ISIL held over 100,000km of territory with a population of 11 million residents.
As ISIL suffered consistent territorial and financial losses, an increasing number of foreign affiliates have returned home. By July 2019, approximately 16 per cent of the 52,808 foreign affiliates that joined ISIL had returned.
In four of the nine regions sending foreign affiliates to ISIL, a higher percentage of male affiliates returned.
Of the 8,202 returnees, seven per cent were female. This may be due to the difficulty of repatriating children born into the caliphate, one of the many complex challenges countries have faced in dealing with former ISIL affiliates.
Globally, an estimated 16 per cent of male affiliates returned from ISIL, compared to nine per cent of female affiliates.
Europe had the largest variation between male and female affiliates who returned. A total of 2,384 affiliates returned, marking 29 per cent of total affiliates who travelled to ISIL from Europe. Of the 4,094 male affiliates, an estimated 45 per cent returned, compared to 18 per cent of female affiliates.
Over 13 per cent of male affiliates from MENA returned, compared to just two per cent of female affiliates.
In Russia and Eurasia, more female affiliates returned compared to male, at 12 per cent and ten per cent respectively.
This was largely because in Kazakhstan, at least 137 females were repatriated as part of Operation Zhusan between January and May 2019. Female returnees faced a rehabilitation and reintegration process, with five facing charges for terror-related offenses.
However, in Russia, approximately two per cent of female affiliates returned, compared to 12 per cent of male affiliates. Until November 2017, Russia was actively repatriating women, after which point only minors were repatriated due to the perceived security risk of female ISIL affiliates.
A number of former female ISIL affiliates remain in Iraq and Syria, possibly due to the difficulty of moving with children. In al-Hol, the largest refugee camp in Syria, approximately 12,000 ISIL affiliates remain, including 4,000 women and 8,000 minors.