While Russia’s military involvement in the war in Syria has received great attention, less focus has been directed at the foreign fighters from Russia and other post-Soviet states who have joined the Islamic State and other Jihadist groups. The emergence of these Jihadists has been a gradual process, which began in the 1990s, and it has now led to a situation where an estimated 7,000 Russians and 3,000 Central Asians are fighting in Syria. These figures present a challenge for the various states fighting the Jihadist groups, but they pose a much greater problem for the Russian and other national authorities, who will have to handle the fighters, when they return home.