I think it is a great insight that every ideology can be turned violent. I first heard this where Zizek cites the book has a story from: "During World War II, Zen Buddhism provided a strong foundation for Japanese militarism, including Imperial Japan's use of suicide warfare."[1] Where a Japanese soldier in WW2 wouldn't do the killing, but his sword (?) This is seen that all ideology can be turned violent.

[1] Brian Daizen Victoria, Zen at War (New York: Weatherhill, 1997).