Military Expansion

In September, 1931, Japanese army officers contrived the "Mukden Incident" (a bomb explosion falsely blamed on the Chinese), giving them an excuse to attack and conquer Manchuria, which was then set up as a puppet state called Manchukuo. In January, 1932, the Japanese bombed and occupied Shanghai. These acts aroused indignation throughout the world; in response to protests at the League of Nations, Japan withdrew from the league.

A minor dash between Chinese and Japanese patrols near Peiping (Beijing) on July 7, 1937, was used as an excuse by the Japanese to launch a general war against China. The United States and other nations protested Japan's aggression and refused to recognize the legitimacy of its conquests. War between the United States and Japan was narrowly averted in late 1937 after Japanese airplanes sank the American gunboat Panay in Chinese waters; Japan apologized and paid damages. By 1940, Japan held virtually all of eastern China and had set up a puppet government there. The Chinese, led by Generalissimo (Commander in Chief) Chiang Kai-shek, continued to resist.

Because the Allied powers were fighting a desperate struggle against Germany and Italy, they could not defend their holdings in Asia, and Japan took advantage of this to increase its strength in the Pacific. On July 18, 1940, under pressure from Japan, Britain closed the Burma Road, over which traveled almost all of the supplies the Chinese armies needed to fight Japan. Japan demanded the use of airfields in French Indochina in June, and began to occupy the northern half of that colony in September. In response, the United States halted exports of scrap iron and steel to Japan, and Britain reopened the Burma Road. On September 27, 1941, Japan signed the Berlin Pact, becoming one of the Axis powers.

Japan demanded, and the Vichy French government granted, full military control of French Indochina in July, 1941. The United States, joined by Great Britain and the Netherlands, froze Japanese assets and imposed a near-total trade embargo against Japan.

Diplomatic Negotiations. In October, 1941, General Tojo Hideki became premier of Japan. Soon after, Japan demanded international recognition of its conquests in China and the right to buy oil in the Netherlands East Indies (now Indonesia). Saburu Kurusu was sent to the United States in November as a special envoy to conduct negotiations between Japan and the American government. At the same time, convinced that negotiations would achieve nothing, Japan was secretly preparing for war against the United States.

The United States pressed for an end to Japanese aggression in China and Japan's withdrawal from French Indochina. Japan, however, issued a declaration of war, which was not delivered until after the surprise attack on the American fleet at Pearl Harbor, Hawaii, on December 7, 1941.