Following the classic work by Roland Bainton, Christian Attitudes toward War and Peace, we will explore the historical presence of three Christian perspectives on war: pacificism, just war thought, and the crusade mentality. We will then discuss the 20th-century revival of just war thought, perhaps best exemplified in "The Challenge of Peace," a letter written by the US Catholic Bishops in 1983. Finally, we will talk about a few recent Protestant contributions to this engaging debate within the Christian faith.