Partick Desbois

Hey everyone!
so I just read an article that was in the NY Times on Saturday entitled "One Story at a Time, a Priest Reveals Ukrainian Jews' Fate".
It's about a French priest who has gone to the Ukraine and other parts of formally Soviet Union. He has interviewed Ukrainians who were forced to work for the Nazi's during Nazi occupation to hear their stories, and has uncovered mass graves that have been largely ignored or covered up over the past 60 years.
Over 1.5 million Jews were murdered in the Ukraine, but until now there it was not publicized to the same extent as in Germany or Poland.
"Over four years, Father Desbois has videotaped more than700 interviews with witnesses and bystanders and has identified more than 600 common graves of Jews, most of them previously unknown."
Why were these landmarks covered up and ignored by the country after other countries revealed their graves and gas chambers? Why didn't these witnesses tell their stories or reveal the graves before now? Would you qualify these people as bystanders? Are they as bad as David Cash? Would you qualify Father Desbois as an upstander (I would)?