Exercise Grand Slam Exercise Grand Slam was an early major naval exercise of the newly formed North Atlantic Treaty Organization ( NATO ) . This 1952 combined naval exercise took place in the Mediterranean Sea , and it included a naval force that was described as being " the largest armada to be assembled in that area since the end of World War II . " Exercise Grand Slam was an early test for NATO ' s Allied Forces Southern Europe . With Exercise Longstep , this exercise served as the prototype for future NATO maritime exercises in the Mediterranean Sea during the Cold War . In January 1950 , the North Atlantic Council approved NATO ' s military strategy of deterring Soviet aggression . NATO military planning took on a renewed urgency following the outbreak of the Korean War in mid - 1950 , prompting NATO to establish a " force under a centralised command , adequate to deter aggression and to ensure the defence of Western Europe " . Allied Command Europe was established under General of the Army Dwight D . Eisenhower , U . S . Army , on 2 April 1951 . The Western Union Defence Organization had previously carried out Exercise Verity , a 1949 multilateral exercise involving naval air strikes and submarine attacks . Command structure . The overall exercise commander for Grand Slam was Admiral Robert B . Carney USN , NATO ' s Commander - in - Chief Allied Forces Southern Europe ( CINCSOUTH ) . AFSOUTH component commanders during Grand Slam were : Operational history . The exercise took place in the Mediterranean Sea between 25 February and 16 March 1952 . Over 200 warships from the U . S . Sixth Fleet , British Mediterranean Fleet , French Mediterranean forces , and the Italian Navy deployed from bases in the British Isles , Southern France , Italy , Gibraltar , Malta , and North Africa for Exercise Grand Slam . The main force was centered around the aircraft carriers , , , and " La Fayette " . Also , the U . S . Marine Corps Battalion Landing Team 3 / 8 ( Reinforced ) was the Landing Force ( Task Force 62 ) for the U . S . Sixth Fleet following its deployment from Morehead City , North Carolina , on 8 January 1952 , returning to Camp Lejeune on 20 May . Marine Detachment , Headquarters Support Activities of CINCSOUTH was activated at Naples , Italy , on 8 March 1952 under the command of Captain Raymond B . Spicer , USMC . Land - based aircraft from all four nations , as well as American , British , and French submarines , rounded out the allied forces involved in this exercise . Allied warships escorted three convoys of supply ships which were subjected to repeated simulated air and submarine attacks . One convoy that departed Malta experienced air attacks every four hours and submarine attacks every five hours during its entire six days at sea . Opposition forces against this particular convoy included the French naval task force , land - based strike aircraft , and carrier - based aircraft from the " Midway " . All three convoys arrived at their respective destinations although with numerous ships declared damaged or sunk by the simulated enemy attacks . Anti - submarine warfare ( ASW ) operations were also executed by the allied navies during Operation Grand Slam . However , a French submarine successfully penetrated the destroyer screen protecting the American - French carrier task force and successfully sank a target within that formation . That French submarine was subsequently declared to be heavily crippled by ASW forces . Finally , a surface force consisting of eight cruisers and ten destroyers carried out a shore bombardment off the Sardinian coast . Carrier aviation units . Carrier Air Group Six embarked on USS " Midway " ( CVB - 41 ) : Carrier Air Group Eight embarked on USS " Tarawa " ( CV - 40 ) : 14th Carrier Air Group embarked on HMS " Theseus " ( R64 ) : Conclusion . The overall exercise commander , Admiral Carney summarized the accomplishments of Exercise Grand Slam by stating : " We have demonstrated that the senior commanders of all four powers can successfully take charge of a mixed task force and handle it effectively as a working unit . " Exercise Grand Slam did receive comparatively little contemporary media coverage . The U . S . Navy ' s " All Hands " magazine noted that Grand Slam was " an exercise which will probably prove typical of future NATO naval exercises . "