No-one can even pretend that the second world war in the East was other than a naked clash between imperialist powers over markets and raw materials.The Second World War started for Japan in 1937, with its attack on China, four years before the attack on Pearl Harbor. The roots of the Pacific side of the conflict, however, went back a century. The seeds of conflict were sown in the unfair treaties enforced by Western powers in the Pacific, nurtured in their maintenance, and the racist exclusion of Eastern nations from equal recognition; and brought to fruit with trade restrictions and the struggle for US-UK naval supremacy.
While Japan had reformed economically under the Tokugawa Shogunate, in the 16th century, its closure to the outside world meant an almost complete lack of an accompanying industrial revolution. This ended in principle with the arrival of Perry in 1853 and his warships, returning a year later to sign an unequal trade agreement at cannon-point. Further unequal agreements with European powers followed. Japan was not the only victim. The pattern began with the British triumph in the First Opium War, leading to the Treaty of Nanking in 1842 (also signed under the threat of British naval bombardment of the city). This was probably what Marx was thinking about when he referred to capitalist trade being the cannons that knocked down Chinese walls. The Chinese were forced to drop tariffs and open ports to trade, without any reciprocation by Britain. The Japanese experience was similar (incidentally, the Japanese learned quickly; they imposed similar unfair agreements on Korea even before Western powers got round to it, in 1876).
This last, Korean example, is probably the key to later developments. The Japanese rulers, or at least the modernising, trade faction, realised that in a world of naked aggression enforcing unequal trade agreements, on a model well-rehearsed by Western powers, they needed to copy the West, build up a strong economy and a strong military, and muscle in on the racket. All of the unequal agreements had been based on humiliating military defeats or demonstrations of raw military technological power. The expression of this was the Meiji Restoration of 1868 : the modernisers promoted their own emperor candidate, and under the slogan "Rich Country, Strong Army" set out to construct a modern Japanese state. The extent of the new, post-treaty Japan was established in 1876 when Japan conceded Sakhalin to Russia, retaining the Kurile Islands. Japan's imperative now was simple: in a country with no mineral resources of note, to build a state of sufficient economic strength and military power to become the ruler of the Western Pacific, cast off the treaties of the West, and impose its own.
The politics of the Meiji Restoration reflected this integral militarism. The Constitution promulgated in 1890 created an extremely strong executive, following the Prussian model, and allowed only an extremely limited franchise (about 5 percent of males, no females) based on a property qualification. In principle, the emperor had unlimited power; this was qualified by the tradition that, in practice, the emperor would not act so imperially. The military answered to the emperor alone, not to the Cabinet. This meant that the military held a constant veto over the cabinet: since only a full cabinet could rule, and the Navy or Army minister had to be from them, either the Navy or the Army could withdraw their minister and bring down the government. This was not a problem at first, but helps explain the later military dominance of the government.
The first objective was control of Korea, in a conflict referred to as the first Sino-Japanese war of 1894-5 : Korea, described as a 'dagger pointing at the heart of Japan', was the subject of pressure from China, but Japan struck first. A quick victory ensued, further weakening the Chinese Qing dynasty: Japan gained Taiwan, other territory, and a large indemnity that was ploughed straight back into industrial development. This was followed by assisting Western powers in the suppression of the Boxer uprising (probably the last straw that led to the fall of the Qing in 1911 and to the new Chinese government of Sun Yatsen). There followed the first match against a Western power, the Russians, in 1904-5: seizure of Port Arthur, the humiliation of the Russian fleet in the straits of Tsushima, and control (later annexation) of Korea and part of Manchuria, saw Japan's re-evaluation by Western powers. By taking back half of Sakhalin, in the Treaty of Portsmouth, Japan also tore up one more of the 'unequal agreements', and established de facto dominance in the area, frustrating Russian ambitions and limiting them to Vladivostok, a port which froze in winter and thus insufficient for their Pacific needs. This was also a show of strength against the Western powers who had overruled Japan at the end of the Sino-Japanese war just a decade previously, forcing them to hand Port Arthur to Russia which Japan had originally wanted for herself.
Anglo-Japanese alliance, signed in 1902, led to Japan's entry on the 'Allied' side in WW1, gaining easy pickings from indefensible German territories both in China and island chains across the Pacific. At Australian and New Zealander insistence, even this early, Japan was limited in acquisitions by latitude and territories in reach of these Australasians which went to the US (which of course had not been idle in the Pacific: having annexed Hawaii in 1898, its war against Spain in 1898-99 yielded almost all of Spain's possessions including the Philippines and Guam). German New Guinea (itself gained out of the disintegration of the Spanish empire in 1899) thus was split into the Marshalls, Carolines, and Marianas for Japan, Samoa for the US, and the Territory of New Guinea formed after WW1 to encompass all the territory that the Australians wanted to control. (The usual 'mandate' agreement').
Thus the battle lines were drawn for World War 2.
The problem was Japan had largely acquired barren lumps of rock. The rich territories of New Guinea were denied them. While some of these lumps of rock were useful (Iwo Jima, for example, does mean 'Sulphur island') and the island chains were rich in fish, by and large Japan had acquired an expensive police operation, while being short of the new naval fuel, oil, required to patrol them and trade between them.
While the US occupied Vladivostok in their attack against the Bolsheviks, the Japanese took the opportunity to occupy every city in the Russian maritime region (the US had asked them to send 7000 troops : the Japanese obligingly sent 70,000). Following the execution of Kolchak and thus the stabilisation of the Bolshevik regime, the US pulled out in 1920, but the Japanese continued their occupation until – note this – being forced to leave in 1922 due to pressure from the US and the British. Anti-Bolshevik policies count for nothing when Realpolitik demands the curbing of an erstwhile ally's power.
The early interwar years were characterised by the disastrous Kanto earthquake (Kanto being the area around Tokyo), which killed 100,000, injured half a million and led to widespread rioting. Much of the damage was due to fires following the quake: the Japanese secret police helped fuel rumours of foreign agents and communist malcontents setting fires, resulting in a double win: the deflection of rioting from the government, and the opportunity to round up political opponents, especially anarchists and Bolsheviks. The cost of rebuilding was only the first economic insult. The Japanese suffered from several economic shocks even before the Great Depression, and their progressive exclusion from the world economy. The vast migration of poor peasant workers to the city, first generation proletarians, caused labour unrest and discontent amongst those who remained on the fields. This rural backlash against the cities, combined with a romanticism of past Samurai history, cemented a firm base for nationalism and militarism outside of the cities – a similar pattern of rural support for nationalism/militarism also pertained in German support for Nazism. Politically, crises consistently led to increasing military control over the government.
Japanese trade was based on the import of raw materials, plus an agricultural sector devoted to silk production, and their working up to produce cheap textiles for the international market. These funds were used to buy what Japan lacked for her heavy industry and military production : coal, oil, scrap steel, and chemicals for munitions and plastics. In short, Japanese expansion was based on women's underwear. The silk trade was devastated by the development of rayon and nylon for stockings; attempts to diversify were more or less unsuccessful. During the Depression, also, the world divided firmly into trade blocs: the Sterling area, the Gold Standard, the Yen Bloc, the Soviets, and the direct transfers that characterised gold-poor Germany. All of these erected strong tariff barriers and strict quotas on goods that they sold themselves: for example, the Sterling Bloc (Imperial Preference) allowed only trivial sales of Japanese textiles due to their own excess production that they expected their colonies to absorb. One of the main reasons for Japanese attacks on China, culminating in the second Sino-Japanese war of 1937, was expanding the Yen bloc and finding markets for their products. The US, insisting on their 'Open Door' policy (basically the legacy of the 'unequal agreements' of the 19th century), imposed progressive sanctions against Japan, culminating in the freezing of Japan's dollar accounts (the most important factor) and the oil embargo. Britain, on the other hand, recognising its weak position vis-à-vis the Japanese, and unable to maintain sufficient fleet assets in the North Sea, Mediterranean, and Singapore simultaneously, was extremely reluctant to antagonise the Japanese, yet forced to stay in step with the US for fear of alienating them in the European struggle. The Dutch were also bullied into trade, but in dollars, and with strict quotas imposed by the US and UK (the UK needed these resources for war; the US wanted to apply pressure).
Japanese military adventure overseas was driven by the army, not the cabinet. The method was the long-held Japanese tradition of 'Gekokujo' or principled insubordination by junior officers, Civil government was thrown into chaos as the army invaded Manchuria in 1931 (an easy victory, followed by problematic pacification campaigns; the Korean resistance movement included Kim Jong-Il as early as 1935, when these forces were absorbed into the Communist forces). In 1937 Japan attacked China, forcing the Nationalists and Communists into an uneasy alliance: and in 1939 the Japanese lost a test of strength against the Russians at Khalkin Gol (though the armistice, on essentially the same border, lasted till 1945). In 1940-41 Japan moved to occupy first part, then all of French IndoChina, following the fall of Franc, This gave them bases in range of Malaya and the Dutch East Indies.
And so we have the recipe for Pacific war. A country with a strong military, an extremely militaristic government and regimented society, and no resources to speak of, bankrupted both by the slings and arrows of outrageous depression economics and the deliberate screw of US policy in China, bogged down in a China whose defence was being funded and stiffened by US funded war materiel passing through UK and French territory, set out to gain by force what was denied them by the rules of peace. Oil in Borneo and Brunei, rubber and tin in Malaya, and above all the ability to pay for what was conquered with yen rather than now non-existent dollars. All this was well known to the allies. The UK in particular had made its plans to defend against the predicted assault, while desperately trying to forestall it. In short, the Japanese attack was one of the least surprising surprise attacks in history. The US simply underestimated their ability to strike at a distance.
The rest, as they say, is history.