The Risks of Foreign Fighters in the Ukraine-Russia Conflict - Legieć, Arkadiusz (Polski Instytut Spraw Międzynarodowych, 2019)
In none of the conflicts in the post-Soviet area have so many foreign fighters participated than in the conflict in eastern Ukraine since 2014. It is estimated that more than 17,000 fighters from 55 countries have fought there on either side. Those fighting on the Russian side pose a special challenge to Ukraine's security and to neighbouring countries because these fighters can engage in terrorism or other radical actions and are part of Russia's hybrid warfare