I doubt that it will ever happen. But if the Vatican were to open its archives, the world would find that the Vatican and the German hieararchy knew infinitely more about what Hitler was up to than you or I can even imagine, with ambassadors to all the important nations and virtual "reporters" in every community of German, tens of millions of Catholics serving in every capacity of the NAZI regime, from the Fuerher himself on down to the grave-diggers of the concentration camps.
Goldhagen's book "Willing Executioners" found that ordinary German citizens not only KNEW what was going on but were WILLING to play whatever role was given to them by the Reich (and blessed by their Catholic and/or Lutheran clergy).
A grand total of 7 Catholics are known to have refused service in Hitler's armies, and some of these were refused the sacraments for doing so.
Before exhonorating "Hitler's Pope" and "Hitler's Bishops", don't people owe it to Hitler's 10 million victims to READ the case against them?
http://www.LiberalsLikeChrist.Org/RCscandal is a good place to start, until you can get some of these:
"German Catholics and Hitler's Wars", by Gordon C. Zahn (a Catholic)
{ U. of Notre Dame Press, 1989 L.O.C. 62-9102 }
"Hitler's Pope, The Secret History of Pius XII", by John Cornwell (a Catholic)
(See what a great many noteworthy critics say about "Hitler's Pope".)
"The Catholic Church in Germany", by Guenter Lewy
"The Popes Against the Jews : The Vatican's Role in
the Rise of Modern Anti-Semitism", by David I. Kertzer
"Under His Very Windows : The Vatican and the Holocaust in Italy"
by Susan Zuccotti
"Unholy Trinity: The Vatican, The NAZIs, and The Swiss Banks",
by Mark Aarons, John Loftus &
"The Secret War Against the Jews : How Western Espionage
Betrayed the Jewish People", by John Loftus, Mark Aarons
"The NAZI Holocaust", by Ronnie S. Landau
"Vatican Diplomacy and the Jews during the Holocaust : 1939-1943",
by Father John F. Morley
"Hitler's Willing Executioners",1996, by Daniel Jonah Goldhagen,
( particularly, pp. 431-441 ) and a whole new book on the topic
"A Moral Reckoning: The Role of the Catholic Church in the Holocaust and Its Unfulfilled Duty of Repair", 2002, by Daniel Jonah Goldhagen
The Abandonment of the Jews", by David Wyman
"Papal Sin : Structures of Deceit", by Garry Wills (a Catholic)
( Doubleday ISBN 0385494106, 2000)
and regarding the record of the Protestant churches,
some of which may have performed even more poorly, read :
"When the Witnesses Were Silent", by Wolgang Gerhach.
"NAZI Terror, The Gestapo, Jews and Ordinary Germans",
by Eric Johnson, a professor of history.
"Blowback : America's Recruitment of NAZIs
and Its Effects on the Cold War", by Christopher Simpson
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One of the favorite books of those who would defend Pius XII is :
"Hitler, the War and the Pope"
by Ronald J. Rychlak (a non-Catholic and associate dean for academic affairs and professor of law at the University of Mississippi School of Law, i.e. not a historian.)