I have heard many opinions from the Church supporting the Nazis, tolerating the Nazi to actively working against the Nazis.
While I am sure to some degree all the above are true for individual priests and bishops, is there any compelling evidence of the Vatican's official position or even official behind the scenes efforts to work against the Nazis?
Thanks in advance for any and all insight.
is there any compelling evidence of the Vatican's official position or even official behind the scenes efforts to work against the Nazis?
The Vatican as a nation was required by the Lateran Accords to observe strict neutrality in foreign affairs. There is some controversy regarding the actions of Pope Pius XII during WWII, and I have addressed that subject here before. Outside of the controversy the consensus is that the pontiff made general statements condemning violence against noncombatants and was largely unfavorable to the Nazis (but not vehemently so in public). The wisdom of this approach is up for debate, as is its efficacy in reducing the damage of the war. As for evidence, there is the Acts and Documents of the Holy See Relative to the Second World War, an 11 volume collection of documents from that period. The full archives are not open (Pope Francis was quoted as saying that they will be opened "soon"), but there have been a couple dozen books written on the subject. Critics of the pontiff say that he took no direct action, while his supporters point to many cases in which the people that took action to help others during the war who directly credit the pope for their motivation (such as Cardinal Roncalli, later Pope John XXIII). In the end it comes down to whether you credit individual acts of conscience to the people involved or to the inspiration of the pope.
As I mentioned, there have been a large number of books on this subject. Most are terrible. These books constitute "the Pius wars" in which the legacy of the wartime pontiff is used as a bludgeon in current political or religious debates. It has little to do with history and much to do with pursuing an agenda, and that goes for both his detractors and his supporters. The sole book that I can unreservedly recommend is Robert Ventresca's Soldier of Christ: The Life of Pope Pius XII, which is a balanced biography with no real axe to grind.
I hope that answers your question. For more information I encourage you to read Ventresca's book and my previously linked post. As always, followup questions from OP and others are encouraged.