The attack severely damaged or destroyed twelve American warships, destroyed 188 aircraft, and killed 2,403 American servicemen and 68 civilians. However, the Pacific Fleet's three aircraft carriers were not in port and so were undamaged, as were the base's vital oil tank farms, submarine pens, and machine shops. Using these resources, the United States was able to rebound within a year.

This attack has also been called the bombing of Pearl Harbor and the Battle of Pearl Harbor but, most commonly, the attack on Pearl Harbor or simply Pearl Harbor.

After the Meiji restoration, Japan embarked on a period of significant economic, political, and military expansion in an apparent effort to achieve parity with the Western Powers who had influence or possessions in East Asia and/or the Pacific. The expansion was heavily influenced by ultra-nationalist members of the government, military, and general society (see also Causes of World War II). In order to fund this expansion, resource-poor Japan embarked on a series of moves that brought it into conflict with neighboring countries, including some of those Powers. These included a war with China in 1894 in which Japan took control of Taiwan, and a war with Russia in 1904 in which Japan gained territory in and around China and the Korean peninsula, and in 1910, took control of the entire Korean peninsula. After WWI, the League of Nations awarded Japan custody of most Imperial German possessions and colonies in the Far East and Pacific waters. In 1931, Japan forcibly established a "puppet" state in Manchuria which they called Manchukuo. In 1937, having made further progress in constructing a large and modern navy and army, Japan began a large-scale invasion of mainland China, attacking from Manchuria and at several points along China's Pacific coast.

The League of Nations, the U.S., the UK, and the Netherlands disapproved of Japan's actions, and responded with diplomatic pressure, condemning various of these moves. Japan left the League of Nations because of its objections to Japanese behavior and policy. Japan 's later aggression in China resulted in U.S. and UK attempts to apply pressure to reduce or reverse Japanese aggression. Japan didn't back down, but instead continued its military campaign in China and formally aligned itself with the Axis Powers in 1940. The U.S. response included economic sanctions, most importantly partial or full embargoes of scrap metal and gasoline and closing the Panama Canal to Japanese shipping, and renouncing previously signed trade agreements between the two countries. Again, the Japanese didn't back down and, in 1941, moved into northern Indochina. The U.S. response was to freeze Japanese assets and initiate a complete oil embargo.