World War II

World War II was the global conflict fought from September 1, 1939, to September 2, 1945, between the Allied powers (principally the United States, United Kingdom, Soviet Union, France, China, and dozens of allied nations) and the Axis powers (Nazi Germany, Japan, and Italy). The war killed an estimated 70 to 85 million people, making it the deadliest conflict in human history. It reshaped the political map of Europe and Asia, ended the European colonial empires, and established the post-war order - including the United Nations, the Bretton Woods financial system, and the Cold War division of the world between U.S. and Soviet spheres.¹

Origins of American Intelligence

The United States entered the war without a centralized foreign intelligence agency. President Franklin D. Roosevelt established the Office of Strategic Services (OSS) under General William J. Donovan in June 1942. The OSS conducted espionage, counterintelligence, psychological warfare, and paramilitary operations in Europe and Asia, and became the institutional ancestor of the Central Intelligence Agency. When President Harry Truman dissolved the OSS in September 1945, many of its personnel were absorbed into the War Department's Strategic Services Unit and subsequently into the Central Intelligence Group (1946) and the CIA (1947).¹

Operation Paperclip and Nazi Recruitment

Among the most consequential intelligence decisions of the immediate post-war period was the U.S. Army and early CIA program to recruit German scientists, intelligence officers, and technical specialists before the Soviet Union could do the same. Operation Paperclip brought more than 1,600 German scientists, engineers, and technicians to the United States, including Wernher von Braun and other rocket scientists central to the American space program. The program was conducted with knowledge that many recruits had committed war crimes; records were sanitized to remove incriminating material.²

Separately, the CIA recruited former SS intelligence officer Reinhard Gehlen, whose Wehrmacht intelligence organization covering the Eastern Front became the Gehlen Organization - and eventually the Bundesnachrichtendienst (BND), West Germany's foreign intelligence service. Gehlen's network provided the CIA's primary human intelligence on Soviet bloc countries during the early Cold War, though it was heavily penetrated by KGB double agents.

General Walter Bedell Smith, who became CIA Director in 1950, had been Eisenhower's wartime chief of staff; dozens of other senior CIA and military intelligence officials in the 1950s-1970s were shaped by wartime OSS service.

MKULTRA and Wartime Research

The MKULTRA program, the CIA's Cold War research effort into mind control and interrogation, grew directly from wartime research. The CIA recruited scientists who had studied the psychological effects of extreme stress and chemical agents during the war, including individuals with knowledge of Nazi medical experiments at concentration camps. The organizational culture of MKULTRA reflected wartime assumptions that extreme measures were justified by existential threat.²

Strategic Significance for the Vault

World War II figures throughout this vault as background context: the formation of the CIA from OSS, the Cold War intelligence relationships born of wartime alliances, the recruitment of former Nazi personnel whose knowledge became part of the Western intelligence apparatus, and the experience of total war that shaped the worldview of the generation of officials who ran the Cold War programs documented here.¹