In 1939 the United States had renounced its trade treaty with Japan and beginning with an aviation gasoline ban in July 1940 Japan had become subject to increasing economic pressure.[98] During this time, Japan launched its first attack against Changsha, a strategically important Chinese city, but was repulsed by late September.[144] Despite several offensives by both sides, the war between China and Japan was stalemated by 1940. To increase pressure on China by blocking supply routes, and to better position Japanese forces in the event of a war with the Western powers, Japan invaded and occupied northern Indochina.[145] Afterwards, the United States embargoed iron, steel and mechanical parts against Japan.[146] Other sanctions soon followed.
In August of that year, Chinese communists launched an offensive in Central China; in retaliation, Japan instituted harsh measures in occupied areas to reduce human and material resources for the communists.[147] Continued antipathy between Chinese communist and nationalist forces culminated in armed clashes in January 1941, effectively ending their co-operation.[148] In March, the Japanese 11th army attacked the headquarters of the Chinese 19th army but was repulsed during Battle of Shanggao.[149] In September, Japan attempted to take the city of Changsha again and clashed with Chinese nationalist forces.[150]
German successes in Europe encouraged Japan to increase pressure on European governments in Southeast Asia. The Dutch government agreed to provide Japan some oil supplies from the Dutch East Indies, but negotiations for additional access to their resources ended in failure in June 1941.[151] In July 1941 Japan sent troops to southern Indochina, thus threatening British and Dutch possessions in the Far East. The United States, United Kingdom and other Western governments reacted to this move with a freeze on Japanese assets and a total oil embargo.[152][153]
Since early 1941 the United States and Japan had been engaged in negotiations in an attempt to improve their strained relations and end the war in China. During these negotiations Japan advanced a number of proposals which were dismissed by the Americans as inadequate.[154] At the same time the US, Britain, and the Netherlands engaged in secret discussions for the joint defence of their territories, in the event of a Japanese attack against any of them.[155] Roosevelt reinforced the Philippines (an American protectorate scheduled for independence in 1946) and warned Japan that the US would react to Japanese attacks against any "neighboring countries
In August of that year, Chinese communists launched an offensive in Central China; in retaliation, Japan instituted harsh measures in occupied areas to reduce human and material resources for the communists.[147] Continued antipathy between Chinese communist and nationalist forces culminated in armed clashes in January 1941, effectively ending their co-operation.[148] In March, the Japanese 11th army attacked the headquarters of the Chinese 19th army but was repulsed during Battle of Shanggao.[149] In September, Japan attempted to take the city of Changsha again and clashed with Chinese nationalist forces.[150]
German successes in Europe encouraged Japan to increase pressure on European governments in Southeast Asia. The Dutch government agreed to provide Japan some oil supplies from the Dutch East Indies, but negotiations for additional access to their resources ended in failure in June 1941.[151] In July 1941 Japan sent troops to southern Indochina, thus threatening British and Dutch possessions in the Far East. The United States, United Kingdom and other Western governments reacted to this move with a freeze on Japanese assets and a total oil embargo.[152][153]
Since early 1941 the United States and Japan had been engaged in negotiations in an attempt to improve their strained relations and end the war in China. During these negotiations Japan advanced a number of proposals which were dismissed by the Americans as inadequate.[154] At the same time the US, Britain, and the Netherlands engaged in secret discussions for the joint defence of their territories, in the event of a Japanese attack against any of them.[155] Roosevelt reinforced the Philippines (an American protectorate scheduled for independence in 1946) and warned Japan that the US would react to Japanese attacks against any "neighboring countries