Exercise Mainbrace

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.

Naval activities in north Atlantic, 1946-1951
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 Norway during World War II confirmed the importance of the region, as Germany was able to establish bases to be established 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 multi-lateral naval exercises, including:


 * Operation Frostbite (pictured), a 1946 naval exercise involving U.S. Navy Task Group 21.11 led by the aircraft carrier USS Midway (CVB-41) that operated in the Davis Straits between Labrador and Greenland;
 * Exercise Verity, a 1949 combined naval exercise involving the British, French, and Dutch navies which carried out naval bombardment, convoy escort, minesweeping, and Motor Torpedo Boat attack evolutions;
 * Exercise Activity, a 1950 Dutch-led naval exercise to refine combined communications and tactical procedures; and
 * Exercise Progress, a 1951 French-led combined naval operation with Belgian, French, Danish, Dutch, Norwegian, and British naval units that participating in antisubmarine warfare operations, air defense maneuvers, minesweeping operations, and convoy exercises.

Soviet containment strategy
Initially with his "long telegram" and subsequently in his article "The Sources of Soviet Conduct" that appeared in the July 1947 issue of Foreign Affairs, American diplomat George F. Kennan argued that Joseph Stalin would not (and moreover could not) moderate the determination of the Soviet Union to undermine and overthrow Western governments following World War II, noting:

"'... the main element of any United States policy toward the Soviet Union must be a long-term, patient but firm and vigilant containment of Russian expansive tendencies... Soviet pressure against the free institutions of the Western world is something that can be contained by the adroit and vigilant application of counterforce at a series of constantly shifting geographical and political points, corresponding to the shifts and manoeuvers of Soviet policy, but which cannot be charmed or talked out of existence.'"

Kennan's advocacy for a policy of containment against the Soviet Union formed the basis of American foreign policy during the Cold War, giving rise to the Truman Doctrine, the Marshall Plan, and the formation of NATO.

NATO command structure
With the establishment of NATO’s Allied Command Atlantic (ACLANT) on 30 January 1952, the Supreme Allied Commander Atlantic (SACLANT) joined the previously created Supreme Allied Commander Europe (SACEUR) as one of the alliance’s two principal military field commanders. Also, a Channel Command was established on 21 February 1952 to control the English Channel and North Sea area and deny it to the enemy, protect the sea lanes of communication, and Support operations conducted by SACEUR and SACLANT.

Operational history
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.

Mainbrace was conducted over twelve days between September 14–25, 1952, and involved nine navies: United States Navy, the British Royal Navy, French Navy, Royal Canadian Navy, Royal Danish Navy, Royal Norwegian Navy, Portuguese Navy, Royal Netherlands Navy, and Belgian Naval Force operating in the Norwegian Sea, the Barents Sea, the North Sea near the Jutland Peninsula, and the Baltic Sea. Its objective was to convince Denmark and Norway that those nations could be defended against attack from the Soviet Union. The exercise featured simulated carrier air strikes against "enemy" formation attacking NATO's northern flank near Bodø, Norway, naval air attacks against aggressors near the Kiel Canal, anti-submarine and anti-ship operations, and U.S. marines landing in Denmark.

Force composition
Eighty thousand men, over 200 ships, and 1,000 aircraft participated in the Mainbrace. The New York Times' military reporter Hanson W. Baldwin described this NATO naval force as being the "largest and most powerful fleet that has cruised in the North Sea since World War I."

USS Franklin D. Roosevelt (CVB-42) with Carrier Air Group 17 (CVG-17):
 * Blue Fleet Fast Carrier Task Force

USS Midway (CVB-41) with Carrier Air Group 6 (CVG-6):

USS Wasp (CV-18) and Carrier Air Group 1 (CVG-1):

HMS Eagle (R05):

HMS Illustrious (R87):


 * 4 Naval Air Squadron
 * 824 Naval Air Squadron
 * 860 Naval Air Squadron - Royal Netherlands Navy


 * Light aircraft carriers
 * USS Wright (CVL-49)
 * HMS Theseus
 * HMCS Magnificent
 * Escort aircraft carriers
 * USS Mindoro (CVE-120)
 * USS Salerno Bay (CVE-110)
 * Battleships
 * USS Wisconsin (BB-64)
 * HMS Vanguard
 * Cruisers
 * USS Quincy (CA-71)
 * USS Columbus (CA-74)
 * USS Des Moines (CA-134)
 * HMS Swiftsure
 * HMCS Quebec
 * Amphibious force flagship
 * USS Mount Olympus (AGC-8)

Gallery
 File:HMS Vanguard - Operation Mainbrace 1952 - I03681.jpg|HMS Vanguard File:USS Midway.jpg|USS Midway File:HMS Vanguard (Battleship, 1946-1960)1.jpg|HMS Vanguard File:Lynde D McCormick.jpg|Admiral McCormick 

Other NATO Military Exercises - Fall 1952
Exercise Mainbrace was part of a series of NATO exercise jointly commanded by Admiral McCormick and General Ridgeway during the Fall of 1952 involving 300,000 military personnel engaged in maneuvers from the Arctic Circle to the Mediterranean Sea.

Two exercises were conducted by NATO's Allied Forces Southern Europe during the Fall of 1952. Ancient Wall was a series of military maneuvers involving ground small unit tactical training, land-based tactical air support, and carrier-based air support. Longstep was a ten-day naval exercise held in the Mediterranean Sea during November 1952 involving over 170 warships and 700 aircraft under the overall command of Admiral Carney. The objective of the Allied ("Blue") forces was to dislodge enemy ("Green") invasion forces from their occupying positions in the Eastern Mediterranean. Blue naval forces were centered around the U.S. Sixth Fleet, under the command of Vice Admiral John H. Cassady, USN, and its two aircraft carriers, the USS Franklin D. Roosevelt (CV-42) and USS Wasp (CV-18). Green forces included submarines and land-based aircraft. The exercise concluded with an amphibious landing at Lebidos Bay south of İzmir, involving 3000 French, Italian, and Greek troops, including the Battalion Landing Team 3/2, under the overall command of General Robert E. Hogaboom, USMC.

Aftermath
The Soviet Union characterized Mainbrace, Holdfast, and other NATO military exercises as "war-like acts" by NATO, with particular reference to the participation of Norway and Denmark, while the USSR was preparing for its own military maneuvers in the Soviet Zone.

Sources and references

 * Sydney Morning Herald - "NATO Ships Enter Baltic Sea" - September 16, 1952
 * Time Magazine, "Operation Mainbrace", September 22, 1952
 * Time Magazine, "NATO: Hedgehogs", September 29, 1952
 * Sydney Morning Herald - "NATO Ships Enter Baltic Sea" - September 16, 1952
 * Time Magazine, "Operation Mainbrace", September 22, 1952
 * Time Magazine, "NATO: Hedgehogs", September 29, 1952
 * Time Magazine, "Operation Mainbrace", September 22, 1952
 * Time Magazine, "NATO: Hedgehogs", September 29, 1952