More than 5,600 supporters of the so-called Islamic State (IS) have allegedly returned to their home countries after IS lost ground in Iraq and Syria. The Soufan Center, a U.S.-based think-tank, has announced that 33 states have reported arrivals in the last two years. This included approximately half of the 850 individuals who have left the UK to allegedly join IS, 400 of the 3,417 fighters from Russia, 760 of the 3,244 from Saudi Arabia, 800 of the 2,926 from Tunisia and 800 of the 2,926. The study stated Russia has sent the most foreign fighters to IS to date. The Soufan Center’s report also stated that IS’s flow of foreign fighters stalled out in the late 2015, as IS began to suffer defeats. The data recovery that followed the recent fall of IS administrative strongholds, such as Raqqa, has confirmed the identities of nearly half of the more that 40,000 foreigners from 110 countries estimated to have flocked to Iraq and Syria to join IS. The report stated that returning women and children will be a particular problem because states may not best know how to reintegrate them. It also cited proper mental and social support mechanisms as key for children returning.