This was a British deception within Field Marshal Sir Archibald Wavell’s India Command (from 25 August Vice Admiral the Lord Louis Mountbatten’s South-East Asia Command) to divert Japanese attentions from the planned Allied offensives in northern Burma, and also toward Akyab and Ramree in the Arakan western coastal region (June/December 1943).
Undertaken by Peter Fleming’s 'D' Division, 'Ramshorn' suggested that British intentions were instead focussed on the recapture of the Andaman islands group in the Bay of Bengal, and the establishment of a major foothold on the island of Sumatra in the Netherlands East Indies.
'Ramshorn' did have the advantage of eliminating the two-prong concept embodied in 'Kjnkajou-Wallaby', and its 'story' was to be that the British forces' primary object was to bring Japanese air power to battle and thus to divert it from the more decisive operations of Major General Claire L. Chennault’s US 14th AAF in China and General Douglas MacArthur’s South-West Pacific Area command in New Guinea and adjacent areas: thus land operations in Burma were essentially to be feints and harassing operations, soon followed by an amphibious assault on the Andaman islands group, and an invasion of Sumatra early on 1944 if reinforcements from the Mediterranean and support from MacArthur could be provided. Fleming recognised that the plan could cause the Japanese to reinforce their position in the Andaman islands group and in Sumatra, both of these objectives of future operations.
When 'Ramshorn' reached the London Controlling Section, Colonel John Bevan disapproved, largely on the basis that Allied strategy against Japan was not yet fixed, and as a result there was no overall deception policy and no deception threats in other Fat Eastern theatres. Bevan recommended that the chiefs-of-staff indicate these factors to Fleming, but on meeting the chiefs-of-staff on 6 August, he was instructed to tell Fleming that until the Far Eastern operational plans had been decided it was unwise to fix any definitive cover plan. Fleming appears to have believed that this permitted him to implement 'Ramshorn' for the rest of 1943 with the means had had on hand, and to have felt that 'Ramshorn' did at least impose on the Japanese the illusion that the Allies were able at any time to undertake major amphibious operations against several objectives.