In 1928, the Republic was nominally unified under the Kuomintang (KMT; also called "Chinese Nationalist Party") after the Northern Expedition, and was in the early stages of industrialization and modernization when it was caught in the conflicts involving the Kuomintang government, the Communist Party of China (founded in 1921), local warlords, and the Empire of Japan. Most nation-building efforts were stopped during the full-scale Second Sino-Japanese War against Japan from 1937 to 1945, and later the widening gap between the Kuomintang and the Communist Party made a coalition government impossible, causing the resumption of the Chinese Civil War, in 1946, shortly after the Japanese surrender to the Allied Powers in September 1945.