This book will analyze and determine whether current United States Marine Corps command and control systems are capable of permitting successful amphibious operations from Over-the-Horizon (OTH). The Marine air-ground task force's (MAGTF), a combined arms force, ability to assault from extended distances with increased lethality, operations tempo, and tactical mobility has increased the options available to the commander. However, OTH brings with it an increasingly complex command and control problem. Diverse mission requirements, limited communication channels, and the need to be able to control widely dispersed forces pose a challenge for the tactical commander. The book first examines two modern command and control theories to provide a theoretical foundation for OTH. It then analyzes two World War operations and a present day exercise to gain practical insights into command and control issues and problems. Examination of the OTH concept will complete the practical data base of the study. The theoretical and practical concepts and data will be compared and examined through a four pronged filter taken from Col Wass de Czege's Urderstanding and Developing Combat Power. These four functional areas will serve as the criterion for analysis. This book concludes that an OTH assault is possible today; however, communications plays a large part in determining the amount of flexibility the MAGTF commander will have. Corrections should include a restructured communications system, new equipment procurement, and a continuation of the education process for its leaders and personnel in the area of command and control.