These trains are a closely guarded military secret in Ukraine. CNN joi… CNN 0 18 09.13 02:43 https://www.youtube.com/watch?v=2gXEwou5w5A + 3 https://www.youtube.com/feeds/videos.xml?channel_id=UCupvZG-5ko_eiXAup… + 2 These trains are a closely guarded military secret in Ukraine. CNN joined one of their journeys