Inter-Service Training and Development Centre

The Inter-Service Training and Development Centre (ISTDC) was a department under the British Chiefs of Staff set up prior to World War II for the purpose of developing methods and equipment to use in Combined Operations.

The ISTDC came into being in May 1938 bringing together representatives from the Royal Navy, Army, and Royal Air Force convened with the portfolio of developing methods and equipment to use in Combined Operations.

The history of amphibious operations in the British Isles reaches back at least as far as Julius Caesar's legions crossing the Channel to invade from Gaul. For centuries the Royal Navy had been landing soldiers on hostile shores, prominent examples being Quebec 1759, Peking 1900, Zeebrugge 1918, and Gallipoli 1915–16. During the inter-war period, however, a combination of recent experience and economic stringency contributed to the delay in procuring equipment and adopting a universal doctrine for amphibious operations.

The costly failure of the Gallipoli campaign during the First World War coupled with the emerging potential of airpower satisfied many in naval and military circles that the age of amphibious operations had come to a close. Still, throughout the 1920s and 1930s, animated discussion in Staff Colleges in Britain and the Indian Army Staff College at Quetta surrounded the strategic potential of the Dardanelles campaign compared with the strategic stalemate of the Western Front. The economic austerity of the worldwide economic depression and the government's adoption of the Ten Year Rule assured that such theoretical talk would not result in the procurement of any equipment.

...
Wikipedia