Ukrainian Oleh Kopko, 31, was summoned to war in August 2014 and spent a year fighting against the Russian-separatist forces in an artillery battalion in eastern Ukraine.Kopko has been in some of the hottest spots of the conflict: He’s been to Debaltsevo, Illovaisk and at the Russian border. He has the warmest memories of his comrades, who were “a real brotherhood.”

His commanders even invited him to rejoin the army as a professional soldier. But Kopko doubts that the invitation will still stand after this story is published.