Operation Mainbrace

Exercise Mainbrace
Part of Cold War (1947–1953)
NATO Northern Flank
Type	NATO combined naval training exercises
Location	North Atlantic Ocean, GIUK Gap, Norwegian Sea, Barents Sea, North Sea, Jutland Peninsula, and Baltic Sea
Planned by	SACLANT & SACEUR
Objective	Deployment of NATO anti-submarine warfare forces, aircraft carrier strike forces, and supply convoys
Date	September 14–25, 1952
Executed by	Admiral Sir Patrick Brind, RN (CINCNORTH)
Outcome	Exercise successfully executed.

Exercise Mainbrace was the first large-scale naval exercise undertaken by the newly established Allied Command Atlantic (ACLANT), one of the two principal military commands of the North Atlantic Treaty Organization (NATO). It was part of a series of NATO exercises jointly commanded by Supreme Allied Commander Atlantic Admiral Lynde D. McCormick, USN, and Supreme Allied Commander Europe General Matthew B. Ridgeway, U.S. Army, during the Fall of 1952.

The strategic importance of control of Norway and the adjacent Norwegian and Barents seas was recognized by Anglo-American naval planners as early as the First World War. The invasion and Occupation of Norway by Nazi Germany during World War II confirmed the importance of the region, as Germany was able to establish bases for submarine and air operations against Allied convoys bound for the Soviet seaport of Murmansk.

Following the Second World War, several former allied navies executed a number of individual and multinational exercises, including:

Initial planning for Exercise Mainbrace was initiated by General Dwight D. Eisenhower prior to his resignation as NATO's Supreme Allied Commander Europe (SACEUR) to run for the President of the United States. The exercise itself was commanded jointly by SACLANT Admiral Lynde D. McCormick, USN, and SACEUR General Matthew B. Ridgeway, U.S. Army, with the immediate theater commander being Admiral Sir Patrick Brind, RN, who was in Commander-in-Chief Allied Forces Northern Europe.