Denys Kostev, a 16-year-old from the southern Ukrainian city of Kherson, initially posted patriotic videos about Ukraine on TikTok and cursed President Vladimir Putin when the war began. But after Russian soldiers visited his orphanage and the frontline drew closer, he was moved against his will to a youth camp in Russian-annexed Crimea.
"It was mandatory," he told the ABC's Foreign Correspondent. "Especially for orphan children in occupied territory, there are no rights."
At the camp, Denys says, Ukrainian language, symbols and music were forbidden. Instead, children were brainwashed with Russian songs, lessons about courage, and stories of great military prowess. He was made to wear the red beret of Russia's "Young Army" cadets and appear in videos praising Russian soldiers and pledging loyalty to Putin.
"It was more of an ideological re-education camp," Denys said. "First, they brainwash you with Russian songs, with some lessons about courage. They tell stories about great military prowess in war."
Denys is one of many Ukrainian children who have been deported or forcibly transferred since 2022, a practice documented by Yale University's Humanitarian Research Lab. Paige Farrenkopf, who leads the investigation team, said the camps are not typical summer holidays: "These are not summer camps where kids are playing in the pool or going to the beach."
Denys eventually escaped and returned to Ukraine. He now warns that Russia's indoctrination system is methodical and long-term. "It's a system that shapes children's minds and ideology over many years," he said. "Russia knows how to do this. They have manuals for it."