Cooperation between China and Germany was instrumental in modernizing the industry and the armed forces of the Republic of China between 1912 and 1941. At the time, China was fraught with factional warlordism and foreign incursions. The Northern Expedition (1928) nominally unified China under Kuomintang (KMT) control, but Imperial Japan loomed as the greatest foreign threat. The Chinese urgency for modernising its military and national defence industry, coupled with Germany's need for a stable supply of raw materials, put China and the German Weimar Republic on the road to close relations from the late 1920s onwards. That continued for a time following the rise of the Nazis in Germany. However, intense cooperation lasted only until the start of the Second Sino-Japanese War in 1937. The German cooperation nevertheless had a profound effect on the modernisation of China and its ability to resist the Japanese during the war. Background The earliest Sino-German trade occurred overland through Siberia, and was subject to transit taxes by the Russian government. To make trading more profitable, Prussia decided to take the sea route, and the first German merchant ships arrived in Qing China, as part of the Royal Prussian Asian Trading Company of Emden in the 1750s. In 1861, after China's defeat in the Second Opium War, the Treaty of Tientsin was signed, which opened formal commercial relations between various European states, including Prussia, with China. In the late 19th century, trade with China was dominated by the British, who operated from Canton at first and later at Shanghai and Hong Kong. German Chancellor Otto von Bismarck sought to establish a foothold in China to offset the British dominance. In 1885, he obtained a steamship subsidy bill and thereby set up direct service to China. The same year, he sent the first German banking and industrial survey group to evaluate investment possibilities, which led to the establishment of the Deutsch-Asiatische Bank in 1890. Those German efforts were second to Britain in trading and shipping in China by 1896. The perception that the Germans were interested only in trade made the Qing government looked to them as a partner to help China's modernization effort. In the 1880s, the German shipyard AG Vulcan Stettin built two of the most modern and powerful warships of its day (the pre-dreadnought battleships Zhenyuan and Dingyuan) for the Chinese Beiyang Fleet. After China's first modernization efforts looked to be a failure