The Second Sino-Japanese War begins
The Marco Polo Bridge Incident is widely viewed as the beginning of the Pacific War, and sometimes considered the start of WWII. Japan's military had a significant presence in the puppet state of Manchukuo, which was established after Japan invaded Manchuria in 1931, and this presence extended along key trading routes into mainland China. Apart from occasional skirmishes, a truce largely maintained peace between Chinese and Japanese forces. However, tensions spilled over at the Marco Polo Bridge in Beijing on July 7, 1937, and fighting ensued. Military commanders ignored subsequent ceasefires or truces, and conflict spilled to other parts of the country. Japan launched a full scale invasion, and took the major cities of Beijing, Shanghai, and Nanjing by the year's end. The invasion of Nanjing became particularly important, not only because it was the capital city at the time, but due to the widespread atrocities committed by the invading forces, where approximately 200,000 Chinese civilians were murdered, in addition to mass rape and looting - the event remains a source of friction between China and Japan to this day.By June 1938, the Japanese had pushed rapidly into China from their foothold in the northeast. They sought to defeat China quickly to prepare for an inevitable clash with the USSR, but China had the numerical advantage and its defenses held firmer than anticipated. The USSR and United States also supported China by providing food, military equipment, and volunteer pilots. In an attempt to prevent the Japanese advance, Chinese nationalist troops destroyed the levees of the Yellow River, diverting one of the world's largest rivers by hundreds of kilometers - this resulted in what has been described as "the largest act of environmental warfare in history", and the flooding killed up to half a million people, displaced up to five million more, and had both immediate and long-term consequences for the region's agricultural output. Despite this, the Japanese were still able to push towards the next major city, Wuhan, which they took by October in a battle that would involve up to 1.5 million troops and result in hundreds of thousands of deaths.
The push stalls
The frontline then became relatively stable for the next three years. The Chinese won some decisive battles as the Imperial Japanese Army tried to push forward, but they did not have the capacity or organization to launch a meaningful counteroffensive. China had been in the midst of a civil war since 1927, mostly between nationalist and communist forces, as well as various warlord factions - despite pausing hostilities following Japan's invasion, there was little coordination between these forces, especially as the war progressed, and internal conflict was still common. In occupied territories, civilian populations created problems for the Japanese through guerilla resistance and non-compliance (i.e. refusal to supply Japan's military), although they suffered greatly through attrition, and up to 250,000 died as Japanese forces used biological warfare to spread diseases such as cholera and even bubonic plague.Japan looks beyond China
In 1940, Japan cut off U.S. aid to China by seizing key airfields in French Indochina, while the German invasion of the USSR in 1941 brought Soviet aid to a halt. The U.S. had maintained its neutrality throughout the invasion of China, and its oil exports met up to 80 percent of Japan's demand. When Japan pushed further into French Indochina in 1941, this was a step too far for the U.S., and the oil supply was cut off in June in an attempt to bring Japan's military expansion to a halt. However, this move did not have the desired effect. Germany's annexation of France and the Netherlands and its aggression against Britain greatly weakened Western influence in Asia, creating an opportunity for the Japanese to pursue its goal of establishing its own economic sphere in the Pacific. Additionally, taking the Dutch East Indies (Indonesia) would give Japan control of the region's largest oil producer, which would replace the U.S. supply - the largest obstacle, however, was the U.S. territory of the Philippines, which lay directly between Japan and the East Indies.Invasion of Southeast Asia
Japanese leadership believed that, regardless of the target, a direct attack on a Western territory would be met by a strong response from the U.S. Pacific Fleet, which had been relocated from California to Hawaii - therefore, the fleet would have to be neutralized for the invasion to have the greatest chance of success. Beginning on the morning of December 8. 1941, Japan launched a wave of surprise invasions, with targets including British Malaya, Burma, the Dutch East Indies, Singapore, Thailand, and the U.S. territories of Guam, Hawaii, the Philippines, and Wake Island. The attack on Pearl Harbor (Dec 7. local time) is the most famous of these, as it officially brought the U.S. into the war, and its success made Japan's larger invasion much easier. The attack on Thailand was also significant as it ended within five hours, and the Prime Minister agreed to a military alliance with Japan. Britain declared war on Japan on the same day many of its territories were attacked - reflecting upon the war years later, Winston Churchill claimed to have "slept the sleep of the saved" on the night of the Pearl Harbor attack, as the U.S. had now joined the Allies, although he did cite the loss of Singapore as the largest defeat in British military history.Apart from unoccupied China, by mid-1942, Japan had taken almost all of East Asia, and controlled a territory that stretched from the borders of the Soviet Union to India and Australia. British Commonwealth forces then held the lines in India and Burma, as well as in New Guinea, just north of Australia. In many territories, the Japanese were initially welcomed as liberators by local populations, however the theft of resources and widespread atrocities saw this goodwill deteriorate quickly. In the Dutch East Indies alone, up to four million people were killed as a result of forced labor, famine, and war crimes.
The Allies push back
In early 1942, most of Australia's armed forces were either fighting in the Mediterranean or Britain's Asian colonies, and the country itself was not prepared to withstand an invasion. However, rather than invade Australia directly, the Japanese pushed into the South Pacific to cut off American supply lines, isolate Australia, and negate any potential threats. Yet, what Japan did not expect was the rapid recovery of the U.S. Navy, which arrived in the South Pacific at the same time as the push into the Solomon Islands. The attack on Pearl Harbor had greatly weakened the U.S. Pacific Fleet, but the three aircraft carriers based there were on patrol during the attack and remained untouched. The role of aerial warfare at sea had not fully been realized in the Pacific, but this changed with the Battle of the Coral Sea and the Battle of Midway - after these battles the Japanese lost most of their fleet carriers, in addition to hundreds of planes and thousands of highly trained personnel. The Imperial Japanese Navy never truly recovered from the Battle of Midway, and the U.S., bolstered by its more extensive shipbuilding program, was able to secure naval dominance by the year's end.Some consider Midway to have been the Pacific War's turning point, while others point to the Guadalcanal Campaign in the Solomon Islands. This was the first major land offensive from the Allies in the Pacific theater, and also involved a series of very costly naval and aerial battles, but the Allies secured victory through their ability to reinforce and resupply their forces after six months of attrition. Australian regulars had also returned from the Mediterranean and reinforced the defense of New Guinea, and the Allies began their northward push from the South Pacific in mid-1943. The Allies used a tactic known as leapfrogging, where they would invade less-fortified islands and then reinforce these positions, while cutting off supply lines to Japan's more-fortified positions. In 1943, Japan was fighting on frontlines in the South Pacific, Burma, and China, trying to maintain control of its occupied territories, and withstand the U.S. attacks at sea. By mid-1944, Japan's resources were incredibly strained, and a massive mobilization campaign was launched to strengthen its armed forces, but to the detriment of its workforce. A massive Japanese offensive in China saw in hundreds of thousands of casualties on both sides, but did little to change the course of the war.
Japan's gradual defeat
The final and largest naval battles of the Pacific War were in 1944, at the Battle of the Philippine Sea (June) and the Battle of Leyte Gulf (October) - in these, U.S. forces slightly outnumbered the Japanese, but it was differences in technology, pilot training and skill, tactics, and shipbuilding that resulted in a crushing defeat of the Imperial Japanese Navy, and the final destruction of its carrier fleet. These battles allowed the U.S to retake the Filipino capital Manila by March 1945, at a huge cost to the civilian population due to atrocities and artillery fire. Thereafter, the U.S. pushed on to take the islands of Iwo Jima and Okinawa in the spring of 1945, which would be used as launching pads for the eventual invasion of the mainland. These battles were two of the costliest of the war for the United States due to fierce resistance, as Japanese troops had been encouraged to fight to the death rather than surrender. The most famous examples of this were the kamikaze pilots at Leyte Gulf and Okinawa, who committed suicide by flying explosive-filled planes into enemy ships, although thousands of Japanese troops also took part in suicidal banzai charges or committed seppuku.In these final two battles, American troops reportedly felt forced to kill the Japanese due to their relentless fighting, and possibly 80-90 percent of Japan's defending forces died in these fights. Additionally, the perceived disregard for Okinawa's civilian population was a matter of concern for the Allied leadership, therefore U.S. generals believed that an invasion of the Japanese mainland would result in a catastrophic death toll for both the military and civilian population, and would come at a high cost for their own forces. In the war's final months, U.S. air raids against Japan intensified, crippling its industry and inflicting heavy losses upon the urban population. The firebombing of Tokyo was particularly severe - Operation Meetinghouse on March 9. was the single most devastating bombing raid in history, and, by some measures, Tokyo was the most bombed city of the entire war.
The war in Europe ended with Germany's surrender in May 1945, at which point the Allies' focus shifted to Japan. The U.S. began preparing for a military invasion of the Japanese mainland, the size of which would have dwarfed the Normandy invasion force by comparison, but alternative measures were taken in an attempt to prevent the incredibly high military and civilian death tolls expected on both sides, and to prevent the USSR from seizing influence in the region. On July 26, the UK, U.S., and China issued the Potsdam Declaration, calling for the complete surrender of Japan - non compliance would mean "prompt and utter destruction". Japan did not surrender and on August 6, the U.S. detonated an atomic bomb over Hiroshima. The U.S. made another call for surrender, which did not come, and on August 9. another atomic bomb was detonated over and Nagasaki. Japan's Prime Minister had claimed that the military would fight until the end, but was secretly trying to negotiate favorable terms of surrender with the Soviet Union - when the the USSR invaded Manchukuo on the same day as the Nagasaki bombing it became clear that such an agreement would not occur. Faced with continued air raids, an imminent invasion, economic collapse and possible further nuclear attacks, Emperor Hirohito announced Japan's surrender on August 15, which was formalized on September 2.
Aftermath
Japan's surrender brought the Second World War to an end. The U.S. moved quickly to occupy the Japanese mainland (the only time in Japan's history where it was occupied by a foreign power), the USSR was prevented from establishing a meaningful influence on the islands, and Japan's overseas territories were redistributed among the Allies. Japan's occupation lasted until 1952, with the U.S. providing humanitarian and financial aid that would help Japan through its reconstruction period. Sweeping reforms were enacted that saw Japan become one of the West's key allies and trading partners during the Cold War, and it was the fastest-growing major economy in the post-WWII era.While Japan was not partitioned in the same way as Germany, South Korea was split along the 38th Parallel, with the north falling under Soviet control and the south under American control - tensions between the opposing governments, who both saw themselves as the legitimate rulers of the peninsula, eventually escalated into a full-scale war from 1950-1953. Although the Korean War is considered the first major conflict of the Cold War era, the Chinese Civil War had resumed before the Second World War had even concluded, with communist forces taking control of the Chinese mainland (the People's Republic of China) by 1949, forcing the nationalists to retreat to Taiwan (the Republic of China). Hostilities largely stopped after this point, yet both governments still maintain their official claim as the sole representative of both territories, although Taiwan's claim has softened in recent decades to dissuade China from economically ostracizing it on the international stage.
Elsewhere in the Pacific, the post-WWII era was defined by decolonization. The European powers that had been displaced by the Japanese often failed to regain the level of control they enjoyed before the war, and independence movements grew stronger. Countries such as Indonesia and Vietnam declared independence immediately after Japan's surrender and engaged in armed struggles to achieve this, whereas countries such as India, the Philippines, or Burma achieved independence through (mostly) non-violent means, and Western powers sought to maintain positive relations with these nascent states and prevent them from falling under communist influence. Today, Japan has fairly positive relations with most of the countries it invaded and is an important trading partner with most in the region, however public opinion of Japan remains unfavorable in some parts, especially China, often due to the actions and atrocities committed during the Second World War.
