On the evening of September 18, 1931, an explosion occurred on the tracks of the South Manchurian Railroad north of the Chinese city of Mukden (today Shen-yang). The railroad was owned and operated by an arm of the Japanese government and its tracks were patrolled by Japanese soldiers. Military leaders immediately blamed Chinese nationalists for the incident and began an occupation of the area; no authorization for this offensive had been given by the government in Tokyo. Japanese soldiers, dispatched from the neighboring colony of Korea, were teamed with railroad security forces, then rapidly and methodically extended their control ever deeper into Manchuria. Mukden and Changchun fell quickly; all of Jilin was in Japanese hands by September 21. The Japanese moved with such precision that it was clear that the offensive had been carefully planned in advance and was not a spur-of-the-moment reaction to a provocative act. The Chinese government at Nanking under Chiang Kai-shek, occupied with confronting recalcitrant warlords and a revitalized Communist rival, could offer little assistance to its countrymen in Manchuria. However, an effective statement was made by a Chinese boycott that proved to be especially strong in Shanghai. The driving force behind the offensive was a rogue Japanese military leadership that feared Chinese unification efforts under Chiang’s Kuomintang. Indeed, a threat to Japanese economic primacy was underway as Chinese groups attempted to build harbor and railroad facilities that would compete directly with the Japanese. In the United States, Secretary of State Henry L. Stimson initially pinned his hopes on the government of Wakatsuki Reijiro, believing that the prime minister would be able to rein in the Japanese military adventurers and bring an end to the crisis. However, Wakatsuki’s party was forced from office in December 1931, in the wake of the public’s overwhelming approval of the Manchurian occupation. The Mukden incident touched off a crisis between Japan and China that would not ease until the following year when the Japanese installed a puppet regime in Manchuria to safeguard their interests.