The Cold War began with an arms race between the United States and the Soviet Union to see who could have more and better weapons. This started after the Soviets were the second country to develop an atomic bomb. In the United States, this started something called the "Military Industrial Complex", which meant business and government working together to spend a lot of money on large-scale weapons projects. Business and government helped each other to get more money and more power. Part of the Complex was something called the Marshall Plan, which rebuilt Europe while making them buy American goods. The Complex allowed for a growing middle class, but also kept the Cold War going.