As the cold war tied science to national security and international blocs, the United States effectively used its dominant scientific position to advance various foreign policy goals, whether the promotion of allied solidarity and anti-communism or the acquisition of foreign markets. Collaborative research during WWII provided an important tie with allies and the United States offered medical and technical aid to enlist Latin American nations. Atomic research, however, tested the limits of cooperation and the United States began restricting allied access before the end of the conflict. At the same time, a suite of international institutions arose championing global governance, whether through agreement on scientific and technical norms or international cooperation in healthcare, agriculture and education. But scientific disputes between the United States and Soviet Union occurred frequently, whether over atomic espionage, the role of new global institutions or cures for cancer. The United States refused to cede oversight to the UN Atomic Energy Commission, pressured the French government to remove left-leaning scientists, limited American support for UN laboratories and required the WHO renounce “social medicine” before receiving support. Finally, the occupations of Germany and Japan provided unique access to science, although employment of Nazi scientists caused embarrassment.