It was the Christian Nation of Nazi Germany(Third Reich) that perpetrated the Holocaust in Europe against the Jews and other population groups.

Many hypocritical Christian nations,and individuals collaborated with the Nazi's and they are as follows:
1.Albania-70% Muslim,Albanian Orthodox 20%,Roman Catholic 10%
2. Austria
3.Belarus
4.Belgium
5.Bohemia
6.Bosnia
7.Channel Islands
8. Czechoslovakia
9.Croatia
10.Denmark
11.Estonia
12.Greece
13.Hungary
14.The Irish Republican Army(IRA)
15.Italy
16.Latvia
17. Lithuania
18. Luxembourg
19.Montenegro
20.Moravia
21.Netherlands
22. Norway
23.Romania
24.Serbia
25.Slovakia
26. Slovenia
27.Soviet Union
28.Ukraine
29.Vichy Government in France
30.Yugoslavia

Also note that 45,000 Norwegians joined the Nazi Party and few Arab Muslim legions fought with the Nazi's in Bosnia,Albania and elsewhere. The governments of Turkestan and South Africa were overt Nazi sympathizers.
How and why did the so-called Christian Nations permit this horrific carnage called the Holocaust ?
Why was the Vatican so silent on the persecution of Jews in 1930's and 1940's ?