Is Assassination Ever Morally Permissible?

Yes, in a time of war, for example. Pope Pius XII supported efforts to assassinate Adolf Hitler during World War II. Scholar Mark Riebling substantiated this in his important book Church of Spies: The Pope’s Secret War Against Hitler. And Riebling’s book, as well as the efforts of others, have led many critics to change their minds about Pius XII.

However, the Church’s “just war” principles would not permit a preemptive assassination of a leader such as Kim Jong Un (CCC 2309). However, actions to impede his launching nuclear weapons would be morally permissible (see CCC 2310ff.).