New and looking to identify Uniform

Hello, I am new to this group. I am trying to identify my Great Grandfather's Uniform in the picture included. I am told that he was in the Ukraine military. But he can have easily been in the NKVD, UPA, or fought in the Red Army. My grandmother was only a teenager when her town was raided and burned down, she was only able to save this picture from her burning home and never seen her parents again. She ended up in Wetzlar DP camp in Germany where she met and married my grandfather, they moved to the US in 1951. She believes she is half Ukranian and half Polish. Any expert help on this would be greatly appreciated.

 

That's stumped me & my son.
We're busy looking at uniforms.
I'll post this link to another website where you asked as it may help other members.
I'm trying to work out the beltbuckle.


Help with identifying the military uniform in this photo.

 

Thank you, I forgot about that other post. It looks like someone may have answered my question in there. I wasn't emailed any notifications in that forum and haven't gone back to check. thank you.