Peace psychology is a subfield of psychology that deals with psychological aspects of peace, conflict, violence, and war. It has four pillars: research, education, practice, and advocacy working towards sustainable peace using non-violent means. It emerged during the Cold War focused on preventing nuclear war, but now takes a more nuanced perspective on different types of violence and meanings of peace. It aims to apply psychological knowledge to promote peace, defined as the absence of destructive conflict and creation of positive social conditions. However, peace psychology faces challenges including perceptions that it is weak, relies too much on qualitative research, and has little to offer other fields like political science.