The Great War was a catastrophic event that shook the world to its core. It was a global thermonuclear war caused by the Sino-American conflict, resulting in the destruction of all participating nations and abroad, global climate disturbance, and billions of casualties due to nuclear explosions, radiation exposure, and the subsequent collapse of social and governmental structures - all within a span of two hours. Though it is impossible to determine which countries were not affected by the war, there are some areas that managed to avoid nuclear consequences. In the Point Lookout DLC for Fallout 3, Point Lookout State Park is described as a place where bombs didn't fall, but the world left them behind.
Today, the United States is still threatened by nuclear disaster - not only from other countries such as North Korea, Iran, or other rogue nations, but also from terrorist groups who could easily access the materials and information needed to build a nuclear weapon.
