Japan in the Interwar Years: What Caused the Japanese Invasion of China?

At the very basic level the Second Sino-Japanese War represents the triumph of Japanese militarism and ultra-nationalism. The eight-year war represented the vindication of state insecurity that, radicalized by an increasingly belligerent Japanese regime in the 1930s, changed the contours of the East Asian order overall. This essay will explore the key facets of Japanese foreign policymaking in regards to its interests on the Chinese mainland through a neoclassical realist lens. In this regard the specific unit level variable of elite threat perceptions will be examined within the national foreign policy apparatus in Tokyo. What is notable in this case is the rising preponderance of a threat model centred on an enduring hostility towards the Soviet Union, put forward by army elites and the militarist faction within the Japanese polity. As will be seen, the salience of this model first developed in inverse proportion to the deficiencies of the civilian government during the 1930-31 economic crisis. This was spurred in no small degree by the proliferation of Gekokujo practices among army officers, who crucially destabilized the civilian government leadership in the process. With this came the 1936 incident that culminated in the rise of the militarist leadership and in consequence the preponderance of a more fatalist and violent brand of foreign policy. In this respect a series of escalatory developments – presented in this essay as exogenous ‘shocks’ – hardened the contours of a looming Soviet-Japanese conflict. This has most notably converged on the pre-emptive need to defeat the Nationalist Chinese government so as to preserve Tokyo’s strategic environment on the East Asian mainland. The intractability of the Japanese army, coupled with the defiance of Chinese nationalism, ultimately led to a devastating conflict that resulted in the deaths of millions. However at the core of this analysis is the more abstract concept of state power, and it is to this that this essay now turns.

Neoclassical realism at the most seminal level maintains that an increase in material capabilities will lead to a corresponding expansion in state intentions.[1] Within the nexus of foreign policy, what does not follow is the uniformity of this process due to its dependence not only on material trends per se, but also on the subjective perceptions of the foreign policy elite. This process entails not only the duties of policymaking but also the task of policy implementation, which in turn depends on the overall strength of existing state apparatuses.[2] In this instance Zakaria introduces the theoretical notion of state power as an intervening variable between state intentions and material capabilities, the latter of which is represented by national power. State power as a conduit of national power thus encompasses the means in which a government may extract for ‘…its purposes and reflects the ease with which central decision-makers can achieve their goals’.[3]

The case of interwar Japan was marked by an ideological dichotomy in regards to the application of state power. In foreign policy terms this pointed to the divergent outlooks of expansionist and diplomacy models put forward by the militarist and internationalist factions respectively. What followed was a set of mutually opposing worldviews that provided starkly different interpretations of national security. This in turn centred on the question of material security in regards to Tokyo’s industrial needs. The first half of the interwar period marked Tokyo’s first attempt at an ‘…economy-oriented foreign policy’ aimed at the creation of a ‘…workable order’ in Asia.[4] In this regard the facet of material security was explained through a preference for free trade and bilateral negotiation. While this remained the status quo throughout the economic growth of the 1920s, the onset of the Great Depression represented an exogenous ‘shock’ that swiftly reconciled Tokyo’s policy elites to the ‘…cumulative effect of long-term trends’.[5] With this crisis came a resurgence in zero-sum thought that sought to align Japanese material security with a more militaristic – and consequently violent – brand of foreign policy.

While not the first economic crisis in post-Meiji history, the crisis of 1930-31 was an externally induced phenomenon that marked the policy limitations of a trade-based foreign policy.[6] This in combination with a series of corruption scandals served to challenge the competence and moral legitimacy of the civilian government.[7] In foreign policy terms this took the form of an imminent sense of national emergency made apparent by severe material shortages that could not be sufficiently addressed due to the narrow partisan interests of the civilian government.[8] In regards to the militarist faction, what transpired at this point was a rectification of state power through a complete overturn of the existing government system. This is in turn centred on the facilitation of a cohesive ideological structure based on the protection and preservation of the imperial will.[9] In material terms this pointed to a foreign policy model that was organized along the zero-sum contours of economic autarky and military expansionism. This was proposed as early as 1928 by prime minister Tanaka Giichi, who openly urged the establishment of a raw materials base on the Chinese mainland driven by a Tokyo-centric regionalist agenda so as to resist the emergence of a united Chinese state.[10]

This belief was reinforced by an increasingly bleak strategic environment in which Tokyo struggled to meet its raw material needs through a thickening web of protectionist restrictions imposed by its former trade partners. This in turn deepened notions of hypocrisy in regards to the supposedly ‘privileged’ geostrategic interests of other great powers.[11] Indeed, Tokyo in furthering its zero-sum argument for the establishment of a raw materials base in the Chinese mainland cited Washington’s self-sufficiency in the ‘…two American continents…’ and the vast British Empire as key precedents.[12] Yet the question still begs: How did this worldview come to replace the heretofore civilian-led internationalist foreign policy framework?

At the very outset the militarist faction – prominently represented within army ranks – has been driven by a strategic culture based on personal sacrifice for the sake of absolute loyalty to the imperial office. In practice this was marked by a tradition of institutional insubordination known as Gekokujo that pointed to a high level of policy activism among mid to lower ranked members of the officer corps.[13] This in turn meant a willingness to tolerate unsanctioned military actions and behaviour if the ends eventually justified the means.[14] Indeed, this was most notably demonstrated in the 1931 Manchurian Incident when a group of mid-level army officers led by Kanji Ishiwara unexpectedly seized control of the Manchurian heartland through a series of covert military operations. In this regard the contours of Tokyo’s strategic environment were irreversibly altered with the emergence of a vast and porous colonial territory on the Chinese mainland. Nevertheless it is fitting to note the fait accompli presented to the foreign policy elite in this instance, as the army command was only notified of the operation once it was already underway.[15] While this wanton act was accepted – and indeed welcomed – out of convenience, it is necessary to note the prevalence of this behaviour among members of the armed forces. Yet there are other ways in which this behaviour has affected the key facets of Japanese state power.

Since the early 1930s the key facets of Tokyo’s foreign policy have remained divergent to the interests of the militarist faction, let alone its foreign policy vision. This was chiefly reflected by the Hamaguchi administration who acceded to Western pressure in the 1930 Washington Naval Conference by agreeing to a naval disarmament plan irrespective of the vehement opposition of the military elites.[16] The consequence of this was a radicalization of domestic policymaking as militarists increasingly sought to compel policy changes through violent coercion. For example, while the disarmament plan was formally ratified by the Diet, Hamaguchi himself was shot and wounded mortally by a member of a militarist society.[17] This in turn gave way to a concatenation of incidents – twenty terrorist incidents, four attempted coups and four political assassinations between 1930 to 1935 alone[18] – that marked the erosion of civilian authority and in extension the structural integrity of Tokyo’s state power structure. Nevertheless these were isolated incidents which lacked a collective show of force that could constitute an existential threat to the political status quo.

The February 26 Incident of 1936 marked the ascendancy of the militarist faction as the principal arbiter of Japanese state power. This was precipitated by a group of mid-level army officers who, with the support of approximately 1600 garrison soldiers, successfully occupied key government buildings in central Tokyo. This was followed by the assassination of various key cabinet officials, including the Finance Minister.[19] Fundamentally, what transpired was a concatenation of military outbursts organized along Gekokujo behavioural strands that aimed to eliminate perceived ‘sources’ of national corruption and in so doing restore the sanctity of the imperial office.[20] This was partially achieved by the near-total elimination of the civilian leadership in Tokyo. The army command, however, succeeded in restoring order by obtaining the surrender of the plotters three days after the coup. With this came a two-tiered approach in asserting militarist primacy over the weakened civilian government: the first was to undertake harsh disciplinary measures against the plotters, the second was to resume the practice of appointing active serving officers to the posts of Army and Navy Minister.[21]

The latter measure marked a direct crossover between militarist and civilian interests within the core of the Japanese state power structure. More pertinently, in so doing the military effectively obtained a forty percent share in the cabinet voting process that granted it veto powers over the cabinet policymaking process.[22] This was in turn used to appoint cabinet members who were sympathetic, or at least not opposed, to militarist interests. In regards to foreign policymaking this pointed to the newfound preponderance of militarist worldviews that meant a more nationalistic and zero-sum interpretation of Tokyo’s strategic environment. This was foremost vindicated by an incremental increase in military spending, which by 1937 would eventually constitute nearly half of the national budget.[23] This was supplemented by renewed plans for total war planning which was to continue until the collapse of the government by 1945. However at the heart of this foreign policy orientation is a deep-seated anxiety towards the ideological hostility of the Soviet Union. It is to this that we now turn.

The 1931 seizure of Manchuria by the Imperial Japanese Army (IJA) confronted Tokyo with the reality of sharing a vast and porous land border with the Soviet Union. At the very outset Tokyo’s elites perceived Moscow’s territorial scope with a profound sense of inferiority and injustice. This was consonant to the broader map of Western imperialism that in zero-sum interpretations pointed to an unequal division of material sources in the Asian continent that constantly favoured the western powers. In strategic parlance Tokyo viewed Moscow as the ‘great landlord’ of the northern hemisphere, denoted by a vast empire that stretched from the Turkic lands to Siberia.[24] This was followed by an inherent hostility among military elites towards the perceived follies of Soviet communism due to a collection of first-hand combat experiences in the Russian civil war of the 1920s.[25] What transpired at this point was a threat model that centred on the material superiority of the vastly numerous Soviet industrial state. This in combination with an aversion to communist influence would ostensibly culminate in an inevitable war between both powers.[26] Indeed, this was most notably reflected by the words of war minister Sadao Araki, who predicted 1936 as the crossover point that would mark the emergence of a progressively stronger Soviet Union and an inversely weaker imperial Japan.[27] A series of exogenous ‘shocks’ related to the increased militarization of the Soviet Far East appeared to reinforce this sense of inevitability.

Moscow, consonant to the heightened state of Japanese military activity in Manchuria throughout the 1930s, adopted an increasingly defensive but no less formidable military posture in the Far Eastern region. This included, among other measures, the construction of large scale border fortifications and a considerable increase in the total number of border garrison units from an average of two in 1932 to twenty in 1934.[28] With this came an increased risk of confrontation at the Soviet-Manchurian border, with alleged border violations reported by both powers totalling one thousand incidents as of 1939.[29] Since the 1930s this geostrategic threat has expanded to include the possible spread of Soviet influence amidst the power vacuum caused by the materially weak Nationalist regime in mainland China. This took the form of political and material support to the Nationalist government in common opposition towards Tokyo’s expansionist aspirations in East Asia. This in turn meant the possible materialization of a covert Sino-Soviet alliance which would directly threaten Tokyo’s interests in Manchuria.[30]

The interwar years in Nationalist China were marked by a period of warlordism that convinced Tokyo’s policy elites of the inherent instability of the Chinese state power structure. In regards to foreign policy this raised concerns on the ideological appeal of Soviet communism as an alternative model of political stability within the Chinese polity. These concerns took the form of a paternalistic attitude stemming from Tokyo’s aversion towards the Soviet regime as well as notions of Japanese moral superiority.[31] In geostrategic terms these suspicions evoked visions of a hegemonic communist monolith that would challenge Tokyo’s expansionary plans on the East Asian mainland.[32] Indeed, this was seemingly vindicated by a non-aggression pact concluded between Nanjing and Moscow in August 1937. In this instance Japanese intelligence interpreted the bilateral agreement as an exogenous ‘shock’ which revealed the depth of communist influence among all social classes in China.[33] To Tokyo’s military elites, what became necessary at this point was a pre-emptive military campaign for the sake of preserving Manchurian – and in extension Tokyo’s – material security. This was organized along the rigid contours of a fatalist line of reasoning based on the intractability of the situation, most notably reflected in War Minister Hideki Tojo’s words that a failure to defeat the Nationalist government while preparing for war against Moscow would be akin to ‘…asking for trouble’.[34]

While Tokyo’s military elites responded to the exogenous ‘shocks’ in the Chinese mainland with swift determination, they remained impervious to a reciprocal set of negative systemic feedback that reflected increasing waves of anti-Japanese hostilities across all Chinese societal levels.[35] This was in fact indicative of a resurgent trend of Chinese nationalism which was rooted in the earliest periods of Japanese colonialism, most notably represented by the 1919 May Fourth Movement. In the 1930s this first took the form of popular outrage directed at Tokyo’s seizure of Manchuria.[36] The resulting impact of popular mobilization on foreign policy was most clearly seen in the 1935 ‘National Salvation Movement’, which consisted of a nationwide series of mass protests and student demonstrations calling for a concerted resistance against Japanese aggression.[37] With this came another ‘shock’ not just to Tokyo’s policy elites – who lost the support of northern Chinese warlords due to popular pressure[38] – but also to the Nationalist elite in regards to the need to militarily confront an increasingly assertive Japan.

In this instance the escalatory tones of a looming Sino-Japanese confrontation were deepened by a concatenation of mob incidents across Chinese urban centres which often resulted in Japanese civilian casualties. A notable case in point was the July 1937 massacre of Japanese residents in Tungchow, which prompted military intelligence chief General Masaharu Homma to characterize army outrage by vowing to avenge these deaths through a series of retaliatory strikes.[39] Consonant to this was an inflated sense of self-confidence among Japanese army ranks that centred on the foregone conclusion of a swift and decisive conflict in China. This was similarly reflected in elite perception levels when Army Minister Sugiyama sought to obtain Emperor Hirohito’s support by promising that war with China would be over in a month.[40] Taken together, the Marco Polo Bridge incident of 1937 went beyond the purviews of a routine clash between Chinese and Japanese garrison units. It marked a meeting point between the threat perceptions of Tokyo and Nanjing centred above all in an increasing inability – and unwillingness – to tolerate the excesses of each other any further. This was sustained by a tidal surge of national determination which presented policy elites with an ‘all-or-nothing’ proposition that was eventually answered by total war.[41]

It is clear that the outbreak of total war was caused by an increasingly belligerent army driven by the urgent task of defeating a weak but defiant China so as to better prepare for an impending war against the Soviet Union. This represented a culmination of struggles between the Japanese policy elites which in theoretical terms centred on the domination of Japanese state power – in this regard the foreign policymaking apparatus in Tokyo – and in extension the capacity to direct the distribution of its material capabilities. These struggles took place within the continuum of the 1930-31 economic crisis, followed by a series of anti-government acts that destabilized the civilian national leadership. The latter pointed to a high level of Gekokujo activism among the officer corps and eventually caused the abrupt transfer of state power from the civilian elites to the militarist faction in the February 26 coup attempt. In foreign policy terms this meant a fatalistic interpretation of Japan’s strategic environment organized along the broad contours of total-war planning and military expansionism, centred above all on an ideologically and militarily hostile industrial power. This essay has provided the tools for assessing the domestic factors that have influenced Tokyo’s interests vis-à-vis its Chinese neighbour in the inter-war period. It is time to move beyond the broad purviews of systemic analysis in interstate relations towards a more concerted emphasis on the unit-level variables that serve to advise and guide a state’s foreign policymaking process, whilst acknowledging and incorporating the prevalent contexts.


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[1] Rose, (1998), 167.

[2] Ibid, 162.

[3] Zakaria, (1999), 39.

[4] Taliaferro, (2016), 185.

[5] Gideon, (2015), 30.

[6] Shizume, (2009), 5.

[7] Storry, (1960), 172.

[8] Nakamura and Tobe, (1988), 521.

[9] Morgan, (2003), 166.

[10] Drea, (2009), 163.

[11] Rothwell, 192.

[12] Ibid, 193.

[13] Coox, (1969), 308.

[14] Yenne, (2014), 16.

[15] Peattie, (1975), 34.

[16] Goldman, (2012), 14.

[17] Ibid, 15.

[18] Drea, (2009), 476.

[19] Harries and Harries, (1991), 183.

[20] Ibid, 184.

[21] Shillony, (1973), 41.

[22] Rothwell, (2005), 192.

[23] Drea, (2009), 488.

[24] Beasley, (1991), 341.

[25] Ibid, 328.

[26] Drea, (2009), 435.

[27] Ibid, 436.

[28] Haslam, (1992), 28.

[29] Goldman, (2012), 18.

[30] Humphreys, (1996), 25.

[31] Nish, (2002), 114.

[32] Drea, (2011), 106.

[33] Nish, (2002), 116.

[34] Ibid, 107.

[35] Taliaferro, (2016), 193.

[36] Westad, (2015), 397.

[37] Peattie, (2011), 73.

[38] Ibid, 73.

[39] Harries and Harries, (1991), 209.

[40] Ibid, 208.

[41] Drea, (2009), 191.


Written by: Chu Kah Leong
Written at: King’s College London
Written for: Dr Giulio Pugliese
Date written: November 2016

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