the Imperial Japanese Army and supported by other right-wing societies. The IJA's nationalism ended civilian rule in Japan until after 1945. The Army, however, was itself divided into cliques and factions with different strategic viewpoints. One faction viewed the Soviet Union as the main enemy; the other sought to build a mighty empire based in Manchuria and northern China. The Navy, while smaller and less influential, was also factionalised. Large-scale warfare, known as the Second Sino-Japanese War, began in August 1937, with naval and infantry attacks focused on Shanghai, which quickly spread to other major cities. There were numerous large-scale atrocities against Chinese civilians, such as the Nanjing massacre in December 1937, with mass murder and mass rape. By 1939 military lines had stabilised, with Japan in control of almost all of the major Chinese cities and industrial areas. A puppet government was set up. In the U.S., government and public opinion—even including those who were isolationist regarding Europe—was resolutely opposed to Japan and gave strong support to China. Meanwhile, the Japanese Army fared badly in large battles with the Soviet Red Army in Mongolia at the Battles of Khalkhin Gol in summer 1939. The USSR was too powerful. Tokyo and Moscow signed a nonaggression treaty in April 1941, as the militarists turned their attention to the European colonies to the south which had urgently-needed oil fields. Latin America The United States launched minor interventions into Latin America. These included military presence in Cuba, Panama with the Panama Canal Zone, Haiti (1915–1935), Dominican Republic (1916–1924) and Nicaragua (1912–1933). The U.S. Marine Corps began to specialize in long-term military occupation of these countries. The Great Depression posed a great challenge to the region. The collapse of the world economy meant that the demand for raw materials drastically declined, undermining many of the economies of Latin America. Intellectuals and government leaders in Latin America turned their backs on the older economic policies and turned toward import substitution industrialisation. The goal was to create self-sufficient economies, which would have their own industrial sectors and large middle classes and which would be immune to the fluctuations of the global economy. Despite the potential threats to United States commercial interests, the Roosevelt administration (1933–1945) understood that the United States could not wholly oppose import substitution. Roosevelt implemented a Good Neighbour policy and allowed the nationalisation of some American companies in Latin America. Mexican President Lázaro