He was one of the civilian Promoters of the Siamese Revolution of 1932 that changed the country's form of government from absolute to constitutional monarchy.

From 1938 to 1947, Direk served in many important posts in the Thai government during the early years of constitutional rule.

[3] Direk’s account is especially good on the Franco-Thai conflict of 1940, the invasion by Japan in 1941, the delicate relationship with Japan over 1942–1943, financial affairs in the immediate postwar period, and the negotiations to rehabilitate Thailand with the Allied Powers, including becoming a member of the United Nations.

[2] It offers undergraduate and graduate studies in three majors, politics and government, public administration, and international affairs.

He was married to Khunying ML Pui, member of the aristocratic Nopawongse royal bloodline, and had 4 sons with her.