fell under the leadership of Jiang Jieshi (Chiang Kai-shek) in the 1920s and expanded rapidly. By 1926 it boasted a powerful national organization and an army of 85,000 troops. The Chinese Communist party also grew to power in the turbulent years of the twenties. Formed in 1921 with advisers, money, and arms from the Soviet Union (and, initially, a political alliance with the Nationalists), the Communist party began to organize workers and students in large numbers. By late 1925, Chinese Communist party membership reached 20,000.26
Both the Nationalists and the Communists represented a new form of mass mobilization whose popular strength was directed first at unloosing the political grip of the warlords. Their challenge to the regional military rulers culminated in the Northern Expedition of 1926–1928. Setting off from Guangzhou in the south, Jiang Jieshi led his army north to Beijing, driving some warlords into retreat and absorbing others into his swelling forces along the way. Uniting the country under the single, centralized political authority of the Guomindang, Jiang's Northern Expedition briefly ended the era of political fragmentation and chaos. Yet soon after unification, the Nationalist-Communist alliance unraveled, leading to the outbreak of a new sort of civil war. The Nationalists emerged as the clear victors in the first phase of conflict. Jiang's bloody surprise attack on Communist organizations in Shanghai in April 1927 and the suppression of Communist-organized “Autumn harvest” insurrections the following fall decimated the Communist movement. Their scattered forces retreated into the hills of the southeast where, under the leadership of Mao Zedong, the peasant-based organization of the People's Liberation Army took shape and developed its strategies of guerrilla warfare. The Communists used these strategies with growing effect, challenging the Nationalist hold over a politically unified China.
Both the Nationalists and the Communists rode to power on the rising tide of anti-imperialist nationalism. The inception of the Chinese Nationalist movement is usually dated from the May Fourth Movement of 1919. After witnessing their own officials at the Paris Peace Conference sell out the former German holdings in Shandong to the interests of Japanese imperialism, enraged students organized a nationwide series of demonstrations. From that point on anti-imperialist protests became an increasingly common occurrence in Shanghai, Hankou, and other foreign centers of manufacture and trade. Merchants and workers joined with students to boycott and strike against foreign enterprises. The protesters frequently singled out British and Japanese firms, since these two nations dominated foreign economic influence in China. Both countries were divided over how to best respond to the Nationalist challenge, flip-flopping from military suppression to appeasement and back again. Coordinated imperialist action was the casualty to such confusion. Thus when the British used force to suppress protest in May and June of 1925, Japanese officials adopted a conciliatory attitude, urging cotton manufacturers to compromise with strikers. Later, when British policy makers decided to back Jiang's moderation against Communist radicalism, their loans and diplomatic support contrasted sharply with Japan's military expeditions to Shandong in 1927 and 1928. What was true for Britain and Japan was equally certain for the other foreign interests in China. Individual national interests overrode advantages of collective action, as bilateral negotiations swept aside the cooperative diplomacy prescribed by the Washington Conference.
In 1929, the collapse of the American stock market and ensuing shock wave of global depression dealt the interimperialist alliance another pro-found blow. All parties responded to the economic crisis with economic nationalism. As they sought to barricade their own interests against any competitors, the imperatives of economic survival seemed to leave less and less room for compromise. To Japanese policy makers this meant sealing off their extensive investments in Manchuria from the rest of China, for special steps seemed necessary to secure a sphere of interest from the forces of Chinese nationalism.
In the Northeast, the rise of the Nationalist movement changed the relationship between Japan and its local collaborators. The increasingly forceful demands for the recovery of economic and political concessions from Japan—expressed in newspapers and through boycotts, strikes, and demonstrations—put pressure on the local warlord Zhang Zuolin to appease some of these demands lest he, like his rivals to the south, find himself the target of nationalist anger. The pressures he was under from nationalist protesters strengthened Zhang's hand in bargaining with the Japanese, who kept up their own demands throughout the 1920s. Zhang maneuvered shrewdly between these two opposing forces, using each as a shield to stave off the other. Although Zhang's repression never permitted boycott and strike activity to reach the intensity it did in the south, whether by accident or design protesters sometimes slipped through his control, as happened in the 1923 Jilin and Qiqihar demonstrations demanding the return of the Kwantung leasehold and railway rights. Japanese officials never entirely believed his protestations of helplessness; they grew increasingly irritated with both Zhang's pleas for patience and his promises to respond to demands later, when nationalist tempers had cooled.27
Even worse, Zhang and his allies were beginning to make investments that would compete with Japanese enterprises and threaten its economic dominance. These included railways and a port facility aimed at creating a parallel Chinese transportation and marketing network in order to break Mantetsu's monopoly. Zhang also established a cotton mill in Fengtian, and his associates created companies for sugar, timber, and coal production. With Zhang's encouragement, Chinese-owned public utilities sprang up, and Chinese merchants opened new businesses throughout the growing cities of the Northeast. While Japanese colonial officials looked on in outrage, the man whose wars they had bankrolled and whose armies they had protected seemed to betray their trust.
Complaints about Zhang's insincerity mounted; but when Kwantung Army officers conspired to resolve the situation by assassinating Zhang, they gravely miscalculated. Zhang Zuolin was succeeded by his son, Zhang Xueliang, who proved to be even less tractable than Zuolin. Well aware of Japan's role in his father's death, Xueliang took his revenge by pushing harder than ever for rights recovery, stepping up investments, and—the crowning blow—signing an agreement with Jiang Jieshi that brought Manchuria under the control of the Guomindang. While this did not mean full political and military integration, Zhang Xueliang now referred all diplomatic matters to the Guomindang, greatly complicating Japanese negotiations concerning Manchuria. Their worst fears appeared to have been realized when Jiang Jieshi announced in the spring of 1931 that the new principles of Guomindang foreign policy included the return of the Kwantung Leased Territory and the recovery of rights to operate Mantetsu.
The sense of crisis among the Japanese in the Northeast intensified, as a fall in profits in the late 1920s seemed to confirm that the nationalist strategy of economic encirclement was working. Though the contraction in colonial revenues was in fact caused by other factors—Mantetsu profits fell due to a drop in world demand for soybeans rather than the Chinese railroad network, and Japanese shopkeepers were imperiled by competition from a Mantetsu consumer co-op and not Chinese merchants—the Japanese blamed it squarely on what they called the “anti-Japanese movement.” Within the various sectors of the colonial state and at every level of colonial society, people compiled catalogs of grievances: obstructions to land purchases, illegal seizures of goods, triple taxing, refusal to permit construction of previously agreed upon railways, unpaid debts, scurrilous newspaper reports, hostility in textbooks, assaults, vandalism, and murder. Settler society organized itself and began to lobby the metropolitan government. Through petitions and speeches they insisted on firm measures to settle the “over 500 pending cases” in what became the catchphrase of an appeal for military intervention.28
Responding in part to these lobbying activities, in part out of their own perception of the gathering crisis, government officials began to discuss options for an independent Manchuria. This was not entirely a new idea, for since the 1911 Revolution Japanese policy makers had flirted with the possibility of severing Manchuria from China. The issue was seriously taken up at the Eastern Conference of 1927, and in 1929 the Kwantung Army began developing operational plans for occupation. Matters came to a head in the summer of 1931, when the Wanbaoshan and Nakamura Incidents became the focal point of agitation for military intervention.
The Wanbaoshan Incident involved a dispute over irrigation rights between 200 immigrant Koreans, whose settlement
