accelerated after the outbreak of the Korean War in June 1950, but much of the necessary equipment and supplies was diverted to the pressing needs of operations in the Korean peninsula. He attended a four-month course at the Armed Forces Staff College in Norfolk, Virginia, and then became chief of the Atomic Section of the Army's Research and Development Division, under the Assistant Chief of Staff, G-4, Lieutenant General Williston B. Palmer, who made him his executive officer in April 1953. In February 1954, Clarke attended the three-month Advanced Management Program at Harvard Business School. He briefly served as head of the Construction Management Branch of G-4, where he was concerned with the funding, manufacture and emplacement of Nike missile batteries. He then became head of the Production Mobilization Branch, with responsibility for the readiness of the national munitions and armament industries, and was special assistant to Palmer's successor, Lieutenant General Carter B. Magruder. He attended the National War College in 1956 and 1957. Clarke's last overseas assignment was as district engineer of the Trans-East District from 1957 to 1959. From his headquarters at Karachi in Pakistan, he oversaw U.S. military construction in Pakistan and Saudi Arabia, and initiated transportation surveys in East Pakistan and Burma. He oversaw $140 million worth of military construction programs (equivalent to $ million in ) in Pakistan alone. Works included Karachi Airport and Dhahran Airport in Saudi Arabia, and design studies for road from Rangoon to Mandalay in Burma, all in support of United States Air Force (USAF) spy flights over the Soviet Union. On returning to the United States in 1959, her served for a year as chief of staff of the United States Army Engineer Training Center at Fort Leonard Wood, Missouri. From 1874 to 1967, the District of Columbia was governed by three federally appointed commissioners (one a civil engineer, selected from the Army Corps of Engineers). On 1 August 1960, President Dwight D. Eisenhower appointed Clarke as the District's Engineer Commissioner. He was the technician-in-chief, called to address the problems such as traffic gridlock, economic development and low levels of funding. At one point early in his term, he was the only commissioner available for full-time duty, because one post was vacant and the other commissioner had suffered a heart attack. In the early 1960s, he participated in talks that led to the compact agreement for construction of the Washington