Despite the period of tensions and internal problems that arise after the war, appeared the idea of cooperation as a tool of unification, and peace and harmony come back.
To reach peace, actually it wasn’t enough with cooperation, they also had to take responsibility for actions done. Give up competences in favor of a European unit.
For that reason, international organizations, as United Nations, appeared. The objectives for that IO were to promote the peace, international security, the development of relations between nations, international solidarity and cooperation. United States, in spite of the internal problems, joined United Nations in October 1945, and took part in international issues.
In August 1946, the country joined the International Court of Justice and among all the important diplomatic questions it was the proposal of control atomic energy and nuclear weapons by United Nations.
In 1947, trying to stop the progress of communism in Europe, it was established Truman doctrine, by which United States supplied army and economic help to the threatened countries.
In other hand, an important base was the Marshall Plan, proposed by George C. Marshall in June 1947. This plan was a program of economic help to rebuild the main European infrastructures destroyed in II World War, with the aim of recovering Europe. United States had to control the expansion of Soviet Union and became the bank of Europe, due to its power. Marshall Plan was rejected by the East countries, subject to Soviet Union.
UNITED STATES 