The Pakistani military remains an opaque entity, both inside and outside of the country. Few publicly available reports exist for those seeking a basic understanding of its leaders, functions, or allegiances. An Introduction to Pakistan's Militaryis the first of two Belfer Center reports examining the Pakistani military. To assemble this report, the authors interviewed over two-dozen retired Pakistani military officers, principally in Islamabad and Karachi. The authors also conducted nearly forty additional interviews with Pakistani politicians, civil society actors, journalists, and military experts, as well as with US and European military, diplomatic, and intelligence officers and analysts.