Text and Web-site by James Bowen, Convener, Pacific War Historical Society. Web-site established May 2002 and last updated 14 May 2010.

Unlike Germany under Adolf Hitler, the territorial expansion of post-restoration imperial Japan was a gradual process that gained momentum as Japan built up its industrial and military strength.

With each successful acquisition of territory by military force, Japan's appetite for territorial expansion appears to have grown. That appetite would lead inexorably to Japan challenging the presence of the United States and Great Britain in East Asia, and to Japan's military attack on Australia in 1942. To provide part of the historical background to the Battle for Australia, and place it in context, this section provides an outline of Japan's territorial expansion between 1875 and 1930. Japan's military aggression in East Asia between 1931 and 1942 follow this section.

An appreciation of nineteenth century European history, and the predominance afforded to Great Britain by its powerful navy, convinced the Japanese that Japan must also have a navy if it was to become a major Pacific power.The Japanese acquired their first pre-dreadnought battleships, including Asahi above, from British shipyards and British naval officers were recruited to train Japan's fledgling Imperial Navy.

In 1874, some Ryuku islanders were ship-wrecked on the coast of Formosa and were murdered by the inhabitants. The Ryuku Islands stretch from Japan's southern home island of Kyushu to the island of Formosa, which at this time belonged to China. When China refused to accept responsibility for the crimes of the Formosans, Japan's imperial government sent a military expedition to Formosa to punish the offenders. As a result of this successful military action, and despite China's protest, Japan claimed that it was the sole legal protector of the kingdom of Ryukyu.

In 1875, the war faction in Emperor Meiji's executive council, led by former samurai from the western Tosa and Saga clans, demanded a military response to Korea firing on a Japanese gunboat engaged in marine surveys off the Korean coast. At this time, Korea was still within China's sphere of influence and able to call on China for military protection. Military action was rejected by the executive council. Although frustrated on this occasion, Japan's militarists would bide their time until a more favourable opportunity came to interfere in Korea's internal affairs.

Japan begins to extend its Frontiers in the Pacific

In 1875, Japan seized the Kuril Islands which stretch from Japan's northern home island of Hokkaido to Russian Siberia. In 1876, Japan seized the Bonin Islands which lie in the Pacific Ocean about 1,300 kilometres to the south-east of the Japanese home islands. In 1879, the Ryuku Islands were formally annexed by Japan and became the prefecture of Okinawa. These three island chain acquisitions provided Japan with defensive island perimeters to the north, east and south of its four main home islands.

Japan's Involvement in Korea

Japanese nationalists felt that Japan also needed to control Korea in order to protect the western approaches to the home islands, and from 1876, Japan involved itself increasingly in Korean internal politics and began to establish a strong economic presence there.

Internal political disorder in Korea in 1882, coupled with an attack by a Korean mob on the Japanese legation at Seoul, led to Japanese troops being sent to Korea to restore order. China also sent an army into Korea. The Chinese government was well aware that Japan's involvement in Korean affairs could threaten its own interests in that country, and it increased Chinese influence in the Korean government. Japan responded by encouraging Korean nationalists to demand full independence from China. In December 1884, Korean nationalists seized their king and called on Japan to intervene to protect them. War between Japan and China was averted by the Treaty of Tientsin in 1885, which required both Japan and China to withdraw their troops from Korea.

Between 1873 and 1894, the peace faction in the imperial government, headed by Hirobumi Ito, had maintained its ascendancy over the militarists, and had prevented Japan becoming involved in war with China over Korea. However, after 1890, obstructive tactics by the national parliament (Diet) would give the militarists an excuse to interfere in Korea's internal affairs. The opportunity came in 1894 when Korea requested China's help in suppressing another rebellion. China warned Japan that it regarded Korea as a tributary or dependent state of China, and would be sending troops to Korea.

The Sino-Japanese War 1894-1895

A number of factors had brought about a political situation favourable to Japan's militarists on this occasion. The need to defend Japan against the threat of foreign military power had always been a high priority of the Meiji imperial government, and it viewed the continuing political instability in Korea as a serious problem because of that country's strategic location on the western approaches to Japan's home islands. The assertion by China, Japan's ancient enemy, of a prior right to intervene in Korea's internal affairs was viewed by the imperial government as raising a threat to Japan's security. There was historical justification for this concern. Mongol armies from China had twice used Korea as a launching point for invasion of Japan in the thirteenth century. Although the invasions were repelled, the invasions undermined central government by the Hojo regency, and led to three centuries of increasing internal disorder.

Since 1885, Tsarist Russia had been showing increasing interest in Korea as a possible avenue for Russian access to the Pacific Ocean by means of a continually ice-free port. This Russian interest in Korea had caused alarm in England, China and Japan. When Russia announced in 1891 its intention to construct the Trans-Siberian Railway for the purpose of linking Moscow to the Russian Pacific port of Vladivostok, Japan viewed this proposal as a threat to its interests in Korea. The Trans-Siberian Railway would bring the military power of Russia to Japan's very doorstep.

In addition to these serious foreign policy issues, the imperial government was troubled by a major domestic problem. The national parliament (Diet) inaugurated in 1890 had not proved as easy to deal with as the imperial government had expected. The Diet had been repeatedly refusing to accept naval estimates presented by the government, and on each occasion, it had required an appeal to the Diet by Emperor Meiji to resolve the deadlock.

In this climate of serious threats to Japan's interests in Korea and continuing parliamentary obstruction of defence budgets, the militarists and bureaucrats in the imperial government joined forces to demand military intervention in Korea. They claimed publicly that this was necessary to protect Japan's vital national interests in Korea, but they privately viewed a foreign war as a useful way to unite all Japanese behind the government in bonds of patriotism, and their views prevailed.

Japanese troops embark at Hiroshima for Korea where they will take part in the first Sino-Japanese War 1894-95

The imperial government rejected China's claim to a special relationship with Korea, and rushed troops to the Korean capital Seoul, where the Japanese and Chinese armies confronted each other. When the Chinese rejected an offer from Japan to work with China to solve Korea's internal problems, Japanese troops seized the king of Korea and replaced his government with a government sympathetic to Japan. The new Korean government then requested that Japanese troops expel China's army from Korea.

Japan's army in Korea was smaller than China's, but it was better trained and organised. The Chinese army suffered successive defeats, and eventually withdrew from Korea and retreated across China's northern region of Manchuria with the Japanese army in pursuit. Japanese troops occupied China's Liaotung Peninsula which projects into the Yellow Sea between China and Korea. Military occupation of this strategically vital peninsula could enable a hostile nation to impede or block access from China's capital Peking (now Beijing) to the Yellow Sea and the Pacific Ocean. China's northern fleet was defeated in a naval battle in the Yellow Sea, and Japanese troops landed on the coast of China's north-east Shantung region. With its capital menaced by Japanese troops from two directions, and its calls for aid from Western powers ignored, China was forced to humble itself and beg Japan for an end to hostilities.

The Treaty of Shimonoseki - Japan imposes harsh Terms for Peace on China

Encouraged by the refusal of Western powers to aid China, Japan's imperial government felt that it could impose harsh terms for peace on China. In 1895, at Shimonoseki on Japan's largest home island of Honshu, the humiliated Chinese government was forced to accept peace terms which included: China to acknowledge Korea's independence; China to surrender to Japan the island of Formosa and the strategic Kwantung Peninsula on the southern coast of Manchuria; heavy monetary compensation to Japan for its costs of the war; and China to provide Japan with generous trading advantages.

The demand that China surrender to Japan the strategic Kwantung Peninsula was a bold one, but it had been forced on the reluctant imperial government by the commanders of Japan's victorious army and navy who were determined to gain a strategic foothold for Japan in this vital area between China and Korea.

Japan's military and naval triumphs against China produced a wave of patriotic fervour in the Japanese people who united in support of the imperial government. Japan had proved itself to be a military power in East Asia. The Diet unanimously approved massive war budgets. The territorial gains and national unity achieved by the imperial government in its first foreign war appeared to justify completely the aggressive foreign policy that had been demanded by the militarists. Japan had taken the first successful step in what would be a vigorous policy of territorial expansion in East Asia.

Russia intervenes to undermine Japan's gains by the Treaty

The party mood in Japan was quickly dispelled by Russian intervention. In its quest for year round access to the Pacific Ocean by means of an ice-free port, Russia had its own secret designs on the Kwantung Peninsula, and in particular, Port Arthur, which was located at the southern tip of the peninsula. Within a week of the Treaty of Shimonoseki being signed, Russia, posing as China's saviour, and with the support of France and Germany, informed Japan that its acquisition of the strategic Kwantung Peninsula posed a threat to peace in East Asia. The three Powers demanded that Japan renounce its acquisition of the Kwantung Peninsula. Despite Britain's refusal to participate in this demand, the military power facing Japan was still formidable, and the imperial government submitted. When the amended Treaty of Shimonoseki was finally ratified at the Chinese port of Chefoo, a menacing Russian naval squadron lay off-shore as a clear warning to Japan's delegates.

When the Japanese public heard that their government had agreed to forgo Japan's claim to the Kwantung Peninsula at the insistence of Russia and other foreign governments, a sense of national humiliation led to widespread public indignation. The fact that Japan's militarists in the imperial government had been too greedy in their demands was lost on the public.

Having ousted Japan from the Kwantung Peninsula, the Russians then called on the Chinese to acknowledge Russia's intervention by permitting the Trans-Siberian Railway to run across Manchuria. Fearing Japan more than Russia, the Chinese agreed. With China having been ousted completely from Korea by the Japanese, and having their own secret designs on the whole of Korea, the Russians then insisted that Japan and Russia become joint "protectors" of Korea. Japan had removed by military force the perceived threat of China as "protector" of Korea, but an even greater menace to Japan in the form of Tsarist Russia had replaced China. While smarting under the continuing humiliations imposed on Japan by Russia, the Japanese militarists would again bide their time until Japan had achieved the military strength to deal with the Russian menace