The United States was a nation in North America. On the Seventh of December in 1941, Japan successfully attacked the major Naval Base that was adjacent to Honolulu by destroying not only the battleships, but also the submarine piers, the power station, shipyard, maintenance, and fuel and torpedo storage facilities, and even the headquarters building were all attacked and damaged. This badly hindered the US, and took them quite a while to send a new fleet.
Once the US had arrived back with their new fleets, they begun suffering heavy losses against the Japanese. By 1944 Japan managed to capture all of Hawaii, and then by 1947, had captured all of Alaska and all other US territories in the Pacific. The US continued fighting against Japan until 1950, in which the Allies decided to sue for peace with them.
Shortly after the war, the US was in a Three Way Cold War with the Soviet Union and Japan.
In 1992, the United States had collapsed after much protests and economic problems, and many new nations were formed out of the former US.