On December 7, 1941, shortly before 8 a.m., Japanese warplanes attacked the United States naval base at Pearl Harbor on Oahu, Hawaii. It was a surprise attack on the American army. The attack on Pearl Harbor was the final element that brought the United States into World War II. Before this attack, Japan had problems with the United States and other major government countries starting in 1915. Japan presented its "Twenty-one Demands" to China. , giving Japan a greater status in certain parts of the country. When the United States implemented the open door policy, Japan's demands were no longer implemented. Later, the Great Depression in the United States worsened Japan's economic problems; they depend on international trade because their island country has few natural resources. To add to their list of problems, Japan was overpopulated and many countries, primarily the United States, had refused entry to Japanese immigrants. Japanese military leaders believed that the only way to solve the country's problems was to invade China. After several aggressions against parts of China, the United States adopted a policy of limiting economic sanctions against Japan, refusing recognition of Japanese military conquests, and providing equal military and economic assistance to China. Japan blamed China's refusal to give in to Japanese terms on foreign interference. The Japanese then wanted to find a way to prevent foreign aid from arriving in China, so that they could then take control of the country. In 1940, Japan viewed Germany as a strong and reliable country to team up with due to its lightning victories. At the time, some territories in Southeast Asia and the South Pacific were controlled by major European powers, such as France, the Netherlands, and Great Britain. It was in the middle of paper...the Nation (12-08-41). " American Rhetoric: Franklin Delano Roosevelt - Pearl Harbor Address to the Nation (12-08-41). Np, nd Web. April 9, 2014. Navy, United States. “The Pearl Harbor Attack, December 7, 1941.” Naval History & Heritage Command, nd Web, April 6, 2014. “Pearl Harbor.” com. A&E Television Networks, nd Web, April 7, 2014. United States and East Asia, 1915-1941. National Endowment for the Humanities, nd Web. April 7, 2014. “USS Arizona Memorial.” USS Arizona Memorial. Arizona Memorial Museum Foundation, nd Web. April 8, 2014..Wohlstetter, Roberta. Pearl Harbor; warning and decision. Stanford, CA: Stanford University Press, 1962. Print.