In 1941, the U.S. made a series of decisions to support China in its war with Japan: Lend Lease supplies were provided after President Franklin D. Roosevelt announced the defense of China to be vital to the defense of the United States. Over the summer, as Japan moved south into French Indo-China, the U.S., Britain and the Netherlands instituted an oil embargo on Japan, cutting off 90% of its supplies. The embargo threatened the operations of the Kwantung Army, which had over a million soldiers deployed in China. Japan responded with a tightly co-ordinated offensive on December 7/8, simultaneously attacking Pearl Harbor, the Philippines, Malaya, Singapore, Hong Kong, Guam, Wake Island, and Thailand.