The Huanggutun Incident (Chinese: 皇姑屯事件; pinyin: Huánggū Tún Shìjiàn), or Zhang Zuolin Explosion Death Incident (Japanese: 張作霖爆殺事件 Hepburn: Chōsakurin bakusatsu jiken), was an assassination plotted and committed on June 4, 1928, by the Japanese Kwantung Army that targeted Fengtian warlord Zhang Zuolin. It took place at the Huanggutun Railway Station near Shenyang, where Zhang's personal train was destroyed by a railside explosion. This incident was concealed in Japan at the time and was referred only as "A Certain Important Incident in Manchuria" (満州某重大事件 Manshu bou judai jiken).
Following the Xinhai Revolution of 1911, China dissolved in spontaneous devolution, with local officials and military leaders assuming power independent of control by the weak central government. In north China the once powerful Beiyang Army split up into various factions after the death of Yuan Shikai in 1916. Zhang Zuolin, being the leader of the Fengtian clique, was one of the most powerful warlords, as he managed to seize control of Manchuria, at the time consisting of nine provinces.
At the time of the First United Front in 1924, foreign support in China was generally divided as follows:
The Fengtian clique's support from abroad was the Empire of Japan, which had vested economic and political interests in the region dating from the end of the Russo-Japanese War and was interested in exploiting their region’s largely untapped natural resources. The Japanese Kwantung Army, based in the Kwantung Leased Territory, also had responsibility for safeguarding the South Manchurian Railway and thus had troops stationed in Manchuria, providing material and logistical support for the Fengtian clique. The cooperation initially worked to the mutual benefit of both parties. Zhang provided security for the railroad and Japanese economic interests, suppressing Manchuria’s endemic banditry problem and allowing extensive Japanese investments. The Imperial Japanese Army assisted Zhang in the two Zhili-Fengtian Wars, including the suppression of the anti-Fengtian uprising by Gen. Guo Songling (a senior Fengtian clique leader). However, Zhang only wanted Japan's aid for consolidating and expanding his territory, whereas Japan envisioned a future joint occupation of Manchuria with Zhang. After Zhang achieved his objectives, he tried to improve relations with the United States and the United Kingdom, allowing both countries open access to the trade, investment and economic opportunities in Manchuria that he had formerly allowed only to the Japanese.
This change in policy came at a time when Japan was in the midst of a severe economic crisis from the Great Kantō earthquake and successive economic depressions, and caused both alarm and irritation in the Kwantung Army leadership. The situation was further complicated by the success of the Northern Expedition led by Chiang Kai-shek of the National Revolutionary Army, in which the Kuomintang successively defeated Sun Chuanfang, Wu Peifu and other warlords of the Northern Faction, as well as the Beijing government controlled by Zhang Zuolin. The Nationalist army appeared poised to restore its rule over Manchuria, which was still officially claimed as part of the Republic of China.
The Nationalists, the Communists and other elements in the Northern Expedition at the time were supported by the Soviet Union, which had already installed puppet governments in nearby Mongolia and Tannu Tuva.
From the Japanese perspective, for Manchuria to fall either under Soviet or Nationalist domination was strategically unacceptable, and Zhang Zuolin no longer appeared trustworthy as an ally capable of maintaining a de facto independent Manchuria. Japan needed a context to effectively establish control over Manchuria without combat or foreign intervention, and it believed splitting up the Fengtian clique via replacement of Zhang with a more cooperative leader would do so.
Outline of the Incident
Zhang left Beijing to go to Shenyang by train on the night of June 3, 1928. The train traveled along the Jingfeng Railway, a route that was heavily patrolled by his own troops. The only location along the railway that was not under Zhang's control was a bridge several kilometres east of Huanggutun Railway Station on the outskirts of Shenyang, where the South Manchuria Railway crossed the Jingfeng Railway on the bridge.
Col. Daisaku Komoto, a junior officer in the Kwantung Army, believed that the assassination of Zhang would be the most expeditious way of installing a new leader more amenable to Japanese demands, and planned an operation without direct orders from Tokyo. His subordinate, Capt. Kaneo Tomiya, was in charge of executing the plan. The bomb itself was planted on the bridge by Sapper 1st Lt. Fujii Sadatoshi. When Zhang's train passed the bridge at 5:23 a.m. on June 4, the bomb exploded. Several of Zhang's officials, including the governor of Heilongjiang province Wu Junsheng (吳俊升), died immediately. Zhang was mortally wounded and sent back to his home in Shenyang. He died several hours later.
At the time of the assassination, the Kwantung Army was already in the process of grooming Yang Yuting, a senior general in the Fengtian clique, to be Zhang’s successor. However, the actual assassination apparently took even the Kwantung Army leadership off guard, as troops were not mobilized and the Kwantung Army was unable to take any advantage by blaming Zhang’s Chinese enemies and using the incident as a casus belli for a Japanese military intervention. Instead, the incident was soundly condemned by the international community and by both military and civilian authorities in Tokyo itself. The emergence of Zhang’s son Zhang Xueliang as successor and leader of the Fengtian clique also came as a surprise.
The younger Zhang, in order to avoid any conflict with Japan and chaos that might provoke the Japanese into a military response, did not directly accuse Japan of complicity in his father's murder, but instead quietly carried out a policy of reconciliation with the Nationalist government of Chiang Kai-shek, which left him as recognized ruler of Manchuria instead of Gen. Yang Yuting. The assassination thus considerably weakened Japan's political position in Manchuria.
Furthermore, the assassination, which was conducted by low-ranking officers, did not have the prior consent of the Imperial Japanese Army General Staff Office or the civilian government. In fact, Emperor Hirohito harshly criticized the event and eventually dismissed Prime Minister Tanaka Giichi for his inability to arrest and prosecute the plotters of the incident, although privately he accepted the military's argument that doing so would be disadvantageous to Japan's military and foreign policy 
In order to achieve its goals in Manchuria, the Kwantung Army was forced to wait several years before creating another incident to justify the invasion of Manchuria and subsequent establishment of the puppet state of Manchukuo under Puyi.
- Jiang, the US and China. Pp. 19
- Beasley, Japanese Imperialism. Pp. 183
- Gordon. A Modern History of Japan. Pp.187
- Beasley, Japanese Imperialism. Pp. 187
- Spence, The Search for Modern China. Pp. 390
- Beasley, Japanese Imperialism. Pp. 188
- Bix. Hirohito and the Making of Modern Japan. pages 216-218 Zhang was a de jure head of state because he held absolute power over the internationally recognized Beiyang government based in Beijing.
- Beasley, W.G. (1991). Japanese Imperialism 1894-1945. Oxford University Press. ISBN 0-19-822168-1.
- Gordon, Andrew (2003). A Modern History of Japan: From Tokugawa Times to the Present. Oxford University Press. ISBN 0-19-511061-7.
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- Spence, Johnathan D. (1991). The Search for Modern China. Norton & Sons. ISBN 0-393-30780-8.