The wars of religion were also waged for "mixed motives." Bohemond took the cross during the First Crusade because the Normans wanted to displace
the Greeks as the dominant power in the East. The Thirty Years War began because the Hapsburg emperor wished to gain control over all of the Holy Roman Empire. The French supported the Swedes rather than Austria because they wished to prevent the Emperor from doing this and surrounding France on three sides. Don't forget that the leader of France was a Cardinal of the Church of Rome, but put politics before his faith, in part because he knew that the Emperor was not engaged in a crusade against the protestants but in
an effort to make the Empire (Germany) the most powerful state in Europe.
Where the Church has used the sword it is because she has forgotten the three temptions of the devil, one of which is worldly power. Christ could not be "turned" but rhe Church often has. Communists, however, subscribe to
a worldy utopia. Not God but blind necessity commands them to do what they do. The atheist does not believe in God but he believes in Demiurge.