Mobility, Vigilance, and Justice: The US Army Constabulary in Germany, 1946-1953 is another in a series of military case studies published by the Combat Studies Institute at Fort Leavenworth, Kansas. This work examines the establishment and operations of the US Constabulary in post-World War II Germany. It outlines the planning involved in the early stages and showcases some of the difficulties involved with implementing the command guidance. The occupation of Germany after World War II is perhaps the paradigm of a successful postcombat operation in modern American history. After four years of bitter fighting, the US Army rapidly shifted from its combat missions and literally reorganized and retrained its forces for its new peacetime role. The US Constabulary in Europe effectively bridged the gap between the victorious Allies and the defeated populace through aggressive law enforcement, border control, and assistance to the Germans in rebuilding their own law enforcement infrastructure. The distinctive uniforms and insignia of the "Circle C" soldiers also served as a constant symbol of the United States' resolve to reconstruct a devastated Germany and help shape it into a trusted friend and ally. The US Army will always need to plan for postcombat operations, and lessons of the US Constabulary are worthy of the attention of commanders, staffs, and soldiers today. This work is general by design and was prepared to provide some insight into the US Constabulary forces that were formed after the end of World War II. Straightforward and to the point, my intent is to showcase the planning of postwar operations and to outline the organization formed to meet the needs of the times. The establishment of a formal constabulary was without precedent in the history of the US Army. After most wars, various units were assigned missions or undertook operations to pacify conquered areas with varying degrees of success. The US Constabulary was radically different. In this instance entire regiments and divisions were dramatically reorganized and rearmed to meet new mission requirements. Personnel who had been trained as artillerymen, engineers, or in some other field found themselves retrained as military policemen. Unit lineage often changed or disappeared altogether. The men of the US Constabulary were the elite of their day. Carefully screened and tested, those who did not make the cut were eliminated. Both Americans and Germans who saw the distinctive uniform and insignia of the US Constabulary knew they were dealing with trained professionals. The sources available to me at the time of this writing are listed in the bibliography but are certainly not all inclusive. There are a number of fine works and monographs on this subject, but the pressures of time and space precluded their use here. The definitive primary source on US Constabulary operations is the Occupation Forces in Europe Series, 1945-1952. This multi-volume set of after-action reports and unit histories is invaluable in studying the specific operations of the US Constabulary and the effect of the unit as a whole. Specifics are not addressed here, but general summaries of this data are incorporated throughout this work.