Template:20th century persecutions of the Catholic Church Conspiracy of Silence is a term used by the Catholic Church since Pope Pius XI to describe the lack of reaction to the persecution of Christians by National Socialism and Communism in such countries as the Soviet Union, Mexico, Germany and Spain
While numerous German Catholics, who participated in the secret printing and distribution of the encyclical, went to jail and concentration camps, the reaction in the Western democracies remained silence, which Pope Pius XI labeled bitterly as a conspiracy of silence.  His protests were not published worldwide and had little resonance at the time in the secular media. 
For the Catholics in Germany, the issuance of the papal protest resulted in increased persecution, for which they experienced largely a lack of publicity and solidarity from Non-Catholics in Western democracies.  The Conspiracy of Silence included not only the silence of secular powers against the horrors of National Socialism but also their silence on the persecution of the Church in the Terrible Triangle.
- Persecutions of the Catholic Church and Pius XII
- Persecution of Christians in the Soviet Union
- Persecution of Christians in Warsaw Pact countries