Operation OVERLORD undoubtedly achieved most of its operational objectives and firmly established the Allied armies on the European Continent. The operation was less than completely successful, however, in that the Supreme Headquarters Allied Expeditionary Force (SHAEF) and European Theater of Operations, U.S. Army (ETOUSA) brought avoidable friction and inefficiencies into the planning and execution of the campaign with respect to the unclear command structure imposed on the field armies and logistics units. Additionally, a poor supply requisition and distribution system created by the Communications Zone (COMZ) necessarily created an inflexible system unable to respond to a rapidly changing combat environment. Finally, SHAEF's decision not to seize key Brittany Peninsula ports and instead devote the bulk of the Twelfth U.S. Army Group (TUSAG) to the pursuit of the German Army across France resulted in the U.S. Army not being able to discharge supplies onto the Continent at a quantity and rate required to sustain the U.S. field armies. Proper adherence to basic tenets of the principles of war most certainly would have resulted in a swifter, less costly prosecution of OVERLORD for the Allies and may have resulted in the war ending in 1944.