How to Bring About “Peace on Earth”? Catholic "Moralities of Warfare" and Their Shifts after 1945

The paper explores how and why Catholic thinking and teaching about war changed during the second half of the 20th century. To do so, I will examine the ways in which the two world wars and the atomic bomb shaped the Catholic perception of modern warfare, outline how declarations of the Roman Catholic Church shifted the official Catholic position, and examine the impact of those changes with regard to West Germany and the United States. I conclude that, while the fundaments of Catholic "moralities of warfare" such as the just war concept, remained unchanged even after 1945, there were essential shifts in what can be said and what can be done about war and peace. These shifts exceeded general Catholic ambiguity on the topic, which had existed for many centuries. Thepaper will discuss how these shifts were linked to other fundamental developments of recent decades, such as the globalisation of the Catholic Church, the pluralisation of the religious field, and the individualisation of life style in Western countries