Sir Olaf Kirkpatrick Kruuse Caroe, KCSI, KCIE (15 November 1892 – 23 November 1981) was an administrator in British India, working for the Indian Civil Service and the Indian Political Service. He served as the Foreign Secretary to the Government of India during the World War II and later as the Governor of the North-West Frontier Province (the frontier with Afghanistan). As Foreign Secretary, he was responsible for reviving the McMahon Line, which included the Assam Himalayan frontier (present day Arunachal Pradesh) within India. After retirement, Caroe took on the role of a strategist of the Great Game and the Cold War on the southern periphery of the Soviet Union. His ideas are believed to have been highly influential in shaping the post-War policies of Britain and the United States. Scholar Peter Brobst calls him the "quintessential master of the Great Game" and the "foremost strategic thinker of British India" in the years before independence.[1]