The first step toward later events like the European Union and the World Trade Organization came when Congress backed international economic cooperation through the Trade Expansion Act
(1962). The act allowed import tariffs to be lowered if reciprocal agreements could be reached with other nations. International negotiations under the Trade Expansion Act were called the Kennedy round in honor of President Kennedy.
The lowering of tariffs was part of the decades long General Agreement on Tariffs and Trade (abbreviated GATT) originally created by the Bretton Woods Conference (1944) as part of a larger plan for economic recovery after World War II. The GATT's main objective was the reduction of barriers to international trade.
Continuing the spirit of the Trade Expansion Act, Europe took a step to being a confederation like the early United States when it established the European Union in 1993. The functions of the GATT were taken over by the World Trade Organization (1995), which was established during the final round of international tariff-lowering in the 1990s.
THE UNITED STATES AS WORLD COP
The U.S. under Eisenhower had been leaning on its huge nuclear arsenal in eye-to-eye confrontations with the Soviet Union, under the horrifying doctrine of Mutually Assured Destruction (aptly known as MAD). The MAD idea was that neither side could start a war because everybody knew both sides would be destroyed.
Under Kennedy, the United States expanded its role as world policeman, even if nobody had actually called the cops. America largely paid for a U.N. force to police violence in the newly independent Congo and helped work out an international agreement to prop up a shaky truce in Laos. These peacekeeping actions called into question the limited military options of the United States; the U.S. military was set up more to defeat other armies than to keep the peace.
Non-nuclear brushfire wars demanded a more flexible response, so Kennedy began to build up elite combat forces such as the Green Berets. These soldiers were supposed to be tough enough to fight anywhere at a moment's notice. They were, but that didn't mean they could control other countries. In the end, having a ready army and a belief that America could do anything led to no-win wars like Vietnam, and later, Iraq and Afghanistan.
American troops could go anywhere, but it was just a waste of lives to have them stay if the local government they supported couldn't win the backing of its own people.