World War II had ended. European countries were worried another person like Hitler might take control and develop massive power in the future. It was also clear that other countries were racing to develop nuclear bombs after America’s threatening demonstration that ended World War II. After WWII there was a rivalry between the communist USSR and the capitalist U.S. and Western Europe which spurred many proxy wars fought for influence over the rest of the world. The Cold War happened because the Soviet Union wanted every country to be communist, but the U.S. and its allies wanted every country to be capitalist. These events contributed to the need for something to protect the European countries from the current Soviet threat and others on the horizon; this would eventually be The North Atlantic Treaty Organization.​​​​​​​​​​​​​

Many crucial events led to the formation of NATO immediately before its creation. One was the Brussels Treaty, the precursor to NATO. It was signed on March 17, 1948, between Britain, France, Belgium, Luxembourg, and the Netherlands to protect from the Soviet threat looming after World War II.​​​​​​​