一20世纪30年代,第一次世界大战后建立起来的国际关系格局发生了重大变化,欧亚战争策源地正在形成。面对日益加剧的战争威胁,美英苏等大国却采取了纵容侵略的绥靖政策。“九·一八”事变后,日本对中国的侵略不断扩大,日益威胁着美国在华利益。美国官方多次表示对日本侵略中国的行为采取"不承认主 In the 1930s, major changes have taken place in the pattern of international relations established after the First World War. The origins of the war in Europe and Asia are taking shape. Faced with the ever-increasing threat of war, the United States, Britain, the Soviet Union and other big powers adopted an appeasement policy of conniving aggression. After the September 18 Incident, Japan’s aggression on China has been constantly expanded, threatening the U.S. interests in China increasingly. On many occasions, the U.S. official has said that it does not recognize the Japanese act of aggression against China