The role of military chaplains has changed over the past decade as Western militaries have deployed to highly religious environments such as East Africa, Afghanistan, and Iraq. US military chaplains, who are by definition non-combatants, have been called upon by their war-fighting commanders to take on new roles beyond providing religious services to the troops to also engage the local citizenry and provide their commanders with assessments of the religious and cultural landscape outside the base. More specifically, in the Balkans, Iraq, and Afghanistan, chaplains have occasionally been asked to provide their commanders with background on the religious and cultural environment to which they deployed (e.g. Islam and the Muslim world) and to reach out to local civilian clerics in hostile territory in pursuit of peace and understanding. Despite some internal resistance to this expansion of duties, some military chaplains have engaged local religious authorities in order to quell misunderstandings and promote peace in the former Yugoslavia, Iraq, Afghanistan, or the Horn of Africa.In this edited volume, practitioners and scholars chronicle the changes that have happened in the field in the 21st century. For example, they explain how the Multi-National Forces-Iraq command chaplain (who reported directly to General Petraeus) worked with the NGO Foundation for Reconciliation and Reconstruction in the Middle East, contributing to a significant drop in sectarian violence. In the Horn of Africa, the command chaplain, who was a Jewish rabbi, helped build relationships between Muslims and Christians. In Afghanistan, Muslim chaplains engaged with Sunni and Shia religious leaders to develop local trust and Coalition and a training program for religious leaders within the Afghan National Army. By looking at the rapidly changing role of the military chaplain, this volume raises issues critical to US foreign and national security policy and diplomacy.