[mehal]

Thank you for pointing it out! Name is definitely Ukrainian, so no russian army, because in Second World War the was Red Army of USSR

[thriftwy]

No Russian Army because he was born around 1914. Otherwise, of course you would find a lot of people with -enko last name in Russian Army in WWI. Not only Russian Empire controlled most of present-day Ukraine but also parts of Poland.

[mehal]

He was captured by Nazis during Second World War