Japanese expansion in East Asia - Causes of expansion

Promulgated in 1889, the Meiji Constitution was Japan's first modern constitution, drafted under Emperor Meiji as part of Japan's rapid modernisation. On paper, it appeared to introduce Western-style constitutional government: it created the Diet, a bicameral parliament made up of an elected House of Representatives and an appointed House of Peers, and it established a cabinet of ministers to advise the Emperor and manage government business.

However, the constitution did not make Japan a parliamentary democracy in the Western sense. Sovereignty was explicitly vested in the Emperor, who was described as 'sacred and inviolable'. The Diet could debate and pass legislation and approve budgets, but it did not control the executive: ministers were responsible to the Emperor, not to the Diet, and the Emperor retained extensive reserve powers, including command of the armed forces, the right to declare war, and the ability to issue emergency ordinances.

This structure also placed other unelected bodies above the Diet in practice. The Privy Council advised the Emperor directly and could block treaties and legislation. The House of Peers, filled with nobility and imperial appointees rather than elected representatives, could obstruct bills passed by the elected lower house. Genro (elder statesmen) and military chiefs likewise operated outside the Diet's authority. The Diet's power over the budget gave it some leverage, but ultimate political authority always rested with the Emperor and the institutions closest to him.

This matters because it explains why the brief flowering of party politics during the Taisho period (1912–1926) — universal male suffrage in 1925, party cabinets from 1918 to 1932 — rested on a fragile, unwritten convention rather than on constitutional guarantee. Nothing in the 1889 document actually required the Emperor to appoint party leaders as Prime Minister, or the military to defer to civilian cabinets. When the constitutional loophole of the right of supreme command was exploited in the 1930s, there was no legal barrier stopping it.

The Meiji Constitution, promulgated in 1889, is the essential starting point for understanding why civilian control over Japan's military collapsed so completely by the 1930s. On paper, the constitution created a modern parliament, the Diet, with an elected lower house. In practice, it declared the Emperor to be sacred and inviolable, the source of all sovereign authority in the state. Ministers were answerable to the Emperor, not to the Diet, and the Emperor's powers included command of the armed forces, the ability to declare war, and the right to issue ordinances. This was not democratic sovereignty dressed in constitutional language -- it was monarchical sovereignty with a parliamentary facade.

The most consequential feature of this arrangement was the right of supreme command, known in Japanese as tosui-ken. This constitutional provision meant the army and navy general staffs reported directly to the Emperor on matters of military command, entirely independent of the Prime Minister or the Cabinet. Civilian politicians had no formal authority over military strategy, deployment, or operations. This was not an informal convention that gradually eroded -- it was written into the 1889 constitution from the outset, decades before the crises of the 1930s.

A second, related mechanism reinforced this divide: convention required that the War Minister and Navy Minister be active-duty military officers. Since a Cabinet could not legally form without these two posts filled, the armed forces could effectively veto a civilian government they disliked simply by refusing to nominate a minister, or by withdrawing one already serving. This gave the military a constitutional lever to bring down cabinets without staging a coup at all.

The Taisho period (1912-1926), named after Emperor Taisho, is remembered as an era of political liberalization in Japan. Under the Meiji Constitution of 1889, Japan had a parliament (the Diet), but ultimate sovereignty rested with the Emperor, and the military reported directly to the throne rather than to elected civilian ministers. Within this framework, the Taisho years nonetheless produced a genuine, if limited, experiment with parliamentary government: party cabinets governed Japan from 1918 to 1932, meaning the prime minister was drawn from the leading party in the Diet rather than appointed as a military or bureaucratic figurehead. This culminated in 1925 with the introduction of universal male suffrage, dramatically expanding the electorate beyond the propertied elite who had previously monopolised the vote.

Two main parties, the Seiyukai and Minseito, competed for power during this period, giving Japan something resembling a functioning two-party system. This was a real shift from the oligarchic politics of the earlier Meiji era, when a small group of elder statesmen (genro) had effectively controlled government behind the scenes. For contemporaries and later historians alike, the Taisho years suggested that Japan might follow a path toward Western-style liberal democracy.

The same year that brought universal male suffrage also brought the Peace Preservation Law (1925), which criminalised any movement seen as threatening the kokutai (the national polity centred on the Emperor). This law was used to suppress communists, socialists, and liberal critics of the system, showing that political liberalization was accompanied by, not opposed to, tightened control over ideological dissent. Party politics was also damaged by its close association with the zaibatsu (large industrial conglomerates such as Mitsui, Mitsubishi, and Sumitomo) and by recurring corruption scandals, which fed a public perception that the Seiyukai and Minseito served big business rather than ordinary citizens, particularly the rural poor.

Taisho Democracy (1912-1926) looked, on the surface, like Japan was becoming a normal parliamentary democracy: party cabinets governed continuously from 1918 to 1932, and universal male suffrage arrived in 1925. But this appearance of democracy sat on top of a constitutional structure -- the Meiji Constitution (1889) -- that had never actually made the Diet sovereign. The Emperor, not the elected parliament, held supreme authority, and several unelected bodies could override or entirely bypass whatever the Diet decided.

Three institutions in particular meant party government was never fully in control. The Privy Council, a body of appointed elder statesmen, could review and block government decisions, including treaties. The House of Peers, the unelected upper house of the Diet, was filled with aristocrats and imperial appointees who could reject legislation passed by the elected House of Representatives. Most decisively, the military chiefs answered directly to the Emperor rather than to the Prime Minister -- this was the right of supreme command (tosui-ken). Because the constitution required a serving officer to fill the posts of War Minister and Navy Minister, the army or navy could bring down a cabinet at any time simply by refusing to nominate one, or by withdrawing an existing minister.

During the Taisho period (1912-1926) and into the early 1930s, Japan's main political parties, the Seiyukai and the Minseito, relied heavily on financial support from the zaibatsu: enormous, family-controlled industrial and financial conglomerates such as Mitsui, Mitsubishi, and Sumitomo. These conglomerates dominated banking, shipping, mining, and heavy industry, and party politicians depended on zaibatsu donations to fund election campaigns and maintain political networks. In return, the zaibatsu expected favourable government policy, contracts, and protection of their commercial interests.

This arrangement was not necessarily illegal, but it created a powerful public perception that Japan's parliamentary system existed to serve big business rather than the ordinary population, particularly the rural poor who made up the majority of Japan's citizens. This perception mattered because it was believed by two groups with the power to act on it: impoverished farmers and the young army officers recruited from farming families.

This perception was reinforced by recurring corruption scandals involving both major parties, which strengthened the image of the Seiyukai and Minseito as self-serving and disconnected from the suffering caused by the agricultural depression and the collapse of silk prices after 1929. Young officers from rural backgrounds, who saw their own families and communities devastated by falling farm incomes, particularly resented what they viewed as a zaibatsu-politician alliance that ignored rural poverty while continuing to profit. This resentment fed directly into the ideology of factions such as the Kodoha (Imperial Way Faction), which called for the destruction of political parties and the zaibatsu alongside direct rule by the Emperor.

During the Taisho period (1912-1926) and into the early Showa years, Japan experimented with party cabinets, which governed continuously from 1918 to 1932. The two dominant parties competing for power were the Seiyukai and the Minseito. On paper, this looked like the maturation of parliamentary democracy in Japan. In practice, both parties became closely associated with corruption, factionalism, and dependence on big business, which steadily eroded public confidence in party government during the years before the military effectively took control of the state.

This perception mattered enormously in the countryside. Rural Japan suffered chronic hardship even before the Great Depression struck, and many farming families depended on cash crops such as silk for survival. When party governments seemed preoccupied with factional infighting, patronage, and business deals in Tokyo, while doing little to address rural distress, the gap between the political elite and ordinary Japanese widened. Corruption scandals involving bribery and favouritism reinforced the image of the Seiyukai and Minseito as self-interested cliques rather than representatives of the nation. This narrative was seized upon by critics of party government, including young military officers, many of whom came from rural backgrounds themselves and resented what they viewed as the zaibatsu-politician alliance's indifference to rural suffering.

The consequence was not merely dislike of particular politicians but a broader delegitimisation of party government as a system. When the Great Depression later devastated the rural economy, the pre-existing image of corrupt, out-of-touch parties made it far easier for ultranationalists and military figures to argue that only direct action, whether by the army or by the Emperor's authority, could address the crisis. The assassinations of party prime ministers Hamaguchi (1930) and Inukai (1932), and the sympathetic public response to the assassins, cannot be fully understood without this backdrop of accumulated resentment toward party politics.

In 1925, the same year the Diet extended the vote to all adult men, it also passed the Peace Preservation Law. On the surface these look like contradictory reforms — one expanding democracy, the other restricting it — but together they reveal how limited Taisho-era liberalization actually was. The law made it a criminal offence to form or join any organization that sought to alter the kokutai (the national polity, centred on the divine authority of the Emperor) or to abolish the system of private property.

In practice, the law was used overwhelmingly against the political left. In 1928, after left-wing parties won eight seats in the Diet election under the new universal suffrage system, the government responded by arresting over 1,000 communists and socialists under the Peace Preservation Law. This shows how the same reform that widened the franchise also gave the state a legal mechanism to neutralize the political groups that reform might otherwise have empowered. Liberals who criticized the military or the constitutional order could also be targeted, since "threatening the kokutai" was defined broadly enough to cover almost any serious challenge to the existing power structure.

The Peace Preservation Law matters for understanding the broader collapse of Taisho Democracy. It demonstrates that even during the high point of party government (1918–1932), the Japanese state retained — and actively used — legal tools to suppress the very pluralism that parliamentary democracy requires. This helped narrow the range of acceptable political opinion well before the military began openly overriding civilian cabinets in the 1930s, making it easier for ultranationalist and militarist voices to dominate public life once party government did collapse after the assassination of PM Inukai in 1932.