The Second World War put an end to American isolationism. The first steps to divert the United States from neutrality took the form of executive agreements (such as the agreement on the destruction of bases of 3 September 1940), which allowed for an increase in aid to England. But it was the important Lend-Lease Act (March 11, 1941) that introduced the United States to the most advanced phase of world diplomacy before Pearl Harbor, while giving a whole new form. Franklin Roosevelt`s bold initiatives, combined with the enormous growth of American economic power, have given a new and unprecedented diplomatic form, that of foreign aid. While traditional diplomacy was conducted between large and small powers and Wilson`s diplomacy established the principle of equality, diplomacy took on a double character after the granting of credit. On the one hand, relations between nations considered equal continued to be led by ambassadors. On the other hand, a new form of relations between two countries has emerged, one becoming the donor and the other the recipient of the aid. The aid, which could be economic, military or technical, was managed by government officials who were not ambassadors and who generally depended only nominally on it. Assistance agreements have generally evolved as follows: first, it has struck down a general law by Congress; Second, the vote on appropriations; third, aid agreements with beneficiaries. The main concern of the American treaties after the Second World War was security cooperation in a post-war climate marked by ideological conflicts with the Soviet Union, the bipolarization of the world between these two powers, the destruction of colonial empires and the emergence of nearly ninety new nations, economic inequality and dependence on nuclear weapons as a deterrent. As a result, the United States has not been able to pursue its traditional (moderate and reserved) contractual policy. Indeed, since 1945, it has entered into more contracts (without agreement) than any other nation, and almost all have been new type.
These included assistance agreements, participation in the United Nations, peace agreements, alliances, deterrence treaties and treaties that address a wide range of issues that traditionally: human rights, ecology, environment and resources, global warming, the prohibition of chemical weapons and other weapons of mass destruction, access to space and future use of space. , copyright and intellectual property protection, as well as biotechnology and human cloning. Instead, the United States would “lend” the deliveries to the British and defer payment. If the payment eventually took place, the focus would not be on paying in dollars. The tensions and instabilities created by the war debt of the 1920s and 1930s had shown that it was unreasonable to expect bankrupt European nations to be able to pay for every item purchased in the United States. Instead, the payment would be mainly in the form of a “counterparty” granted by Great Britain to the United States. After months of negotiations, the United States and Great Britain agreed in Article VII of the Lend Lease Agreement they signed that this reflection would consist mainly of common measures to create a liberalized international economic order in the post-war world. Despite many disagreements, Allied leaders managed to reach some agreements in Potsdam. Negotiators thus confirmed the status of Germany demilitarized and disarmed among the four zones of the Allied occupation. According to the protocol of the conference, there should be “complete disarmament and demilitarization of Germany”; all aspects of German industry that could be used for military purposes should be removed; all German military and paramilitary forces should be eliminated; and the manufacture of all military equipment in Germany was prohibited.