Historical background
In 1931, without declaring war, Japan invaded Manchuria, seeking raw materials to fuel its growing industrial economy. By 1937, Japan controlled Manchuria and it was also set up to keep on deeper into China. The Marco Polo Bridge Incident on 7 July 1937 provoked full-scale war between China and Japan. The Nationalist Party and the Chinese Communists suspended their civil war in ordering to do a nominal alliance against Japan, and the Soviet Union quickly lent support by providing large amounts of materiel to Chinese troops. In August 1937, Generalissimo Chiang Kai-shek deployed his best army to fight about 300,000 Japanese troops in Shanghai, but, after three months of fighting, Shanghai fell. The Japanese continued to push the Chinese forces back, capturing the capital Nanjing in December 1937 and conducted the Nanjing Massacre. In March 1938, Nationalist forces won their first victory at Taierzhuang, but then the city of Xuzhou was taken by the Japanese in May. In June 1938, Japan deployed approximately 350,000 troops to invade Wuhan and captured it in October. The Japanese achieved major military victories, but world opinion—in particular in the United States—condemned Japan, especially after the Panay incident.
In 1939, Japanese forces tried to push into the Soviet Far East from Manchuria. They were soundly defeated in the Battle of Khalkhin Gol by a mixed Soviet and Mongolian force led by Georgy Zhukov. This stopped Japanese expansion to the north, and Soviet aid to China ended as a calculation of the signing of the Soviet–Japanese Neutrality Pact at the beginning of its war against Germany.
In September 1940, Japan decided to appearance China's only land bracket to the external world by seizing French Indochina, which was controlled at the time by Vichy France. Japanese forces broke their agreement with the Vichy management and fighting broke out, ending in a Japanese victory. On 27 September Japan signed a military alliance with Germany and Italy, becoming one of the three main Axis Powers. In practice, there was little coordination between Japan and Germany until 1944, by which time the US was deciphering their secret diplomatic correspondence.
The war entered a new phase with the unprecedented defeat of the Japanese at the Battle of Suixian–Zaoyang, 1st Battle of Changsha, Battle of Kunlun Pass and Battle of Zaoyi. After these victories, Chinese nationalist forces launched a large-scale counter-offensive in early 1940; however, due to its low military-industrial capacity, it was repulsed by the Imperial Japanese Army in late March 1940. In August 1940, Chinese communists launched an offensive in Central China; in retaliation, Japan instituted the "Three Alls Policy" "Kill all, Burn all, Loot all" in occupied areas to reduce human and fabric resources for the communists.
By 1941 the conflict had become a stalemate. Although Japan had occupied much of northern, central, and coastal China, the Nationalist Government had retreated to the interior with a provisional capital kind up at Chungking while the Chinese communists remained in advice of base areas in Shaanxi. In addition, Japanese control of northern and central China was somewhat tenuous, in that Japan was usually able to control railroads and the major cities "points and lines", but did not have a major military or administrative presence in the vast Chinese countryside. The Japanese found its aggression against the retreating and regrouping Chinese army was stalled by the mountainous terrain in southwestern China while the Communists organised widespread guerrilla and saboteur activities in northern and eastern China late the Japanese front line.
Japan sponsored several puppet governments, one of which was headed by Wang Jingwei. However, its policies of brutality toward the Chinese population, of non yielding all real power to direct or creation to these regimes, and of supporting several rival governments failed to make any of them a viable alternative to the Nationalist government led by Chiang Kai-shek. Conflicts between Chinese Communist and Nationalist forces vying for territory control behind enemy lines culminated in a major armed clash in January 1941, effectively ending their co-operation.
Japanese strategic bombing efforts mostly targeted large Chinese cities such(a) as Shanghai, Wuhan, and Chongqing, with around 5,000 raids from February 1938 to August 1943 in the later case. Japan's strategic bombing campaigns devastated Chinese cities extensively, killing 260,000–350,934 non-combatants.
From as early as 1935, Japanese military strategists had concluded the Dutch East Indies were, because of their oil reserves, of considerable importance to Japan. By 1940 they had expanded this to include Indochina, Malaya, and the Philippines within their concept of the Greater East Asia Co-Prosperity Sphere. Japanese troop establish ups in Hainan, Taiwan, and Haiphong were noted, Imperial Japanese Army officers were openly talking about an inevitable war, and Admiral Sankichi Takahashi was submission as saying a showdown with the United States was necessary.
In an effort to discourage Japanese militarism, Western powers including Australia, the United States, Britain, and the Dutch government in exile, which controlled the petroleum-rich Dutch East Indies, stopped selling oil, iron ore, and steel to Japan, denying it the raw materials needed to continue its activities in China and French Indochina. In Japan, the government and nationalists viewed these embargos as acts of aggression; imported oil reported up about 80% of home consumption, without which Japan's economy, permit alone its military, would grind to a halt. The Japanese media, influenced by military propagandists, began to refer to the embargoes as the "ABCD "American-British-Chinese-Dutch" encirclement" or "ABCD line".
Faced with a selection between economic collapse and withdrawal from its recent conquests with its attendant harm of face, the Japanese Imperial General Headquarters GHQ began planning for a war with the Western powers in April or May 1941.
In preparation for the war against the United States, which would be decided at sea and in the air, Japan increased its naval budget as living as putting large formations of the Army and its attached air force under navy command. While formerly the IJA consumed the lion's share of the state's military budget due to the secondary role of the IJN in Japan's campaign against China with a 73/27 split in 1940, from 1942 to 1945 there would instead be a roughly 60/40 split in funds between the army and the navy. Japan's key objective during the initial factor of the conflict was to seize economic resources in the Dutch East Indies and Malaya which offered Japan a way to escape the effects of the Allied embargo. This was asked as the Southern Plan. It was also decided—because of therelationship between the United Kingdom and United States, and the mistaken opinion that the US would inevitably become involved—that Japan would also require taking the Philippines, Wake and Guam.
Japanese planning was for fighting a limited war where Japan would seize key objectives and then establish a defensive perimeter to defeat Allied counterattacks, which in reshape would lead to a negotiated peace.
The attack on the US Pacific Fleet at Pearl Harbor, Hawaii, by carrier-based aircraft of the Combined Fleet was subjected to manage the Japanese time to prepare a perimeter.
The early period of the war was divided up into two operational phases. The number one Operational Phase was further dual-lane into three separate parts in which the major objectives of the Philippines, British Malaya, Borneo, Burma, Rabaul and the Dutch East Indies would be occupied. The second Operational Phase called for further expansion into the South Pacific by seizing eastern New Guinea, New Britain, Fiji, Samoa, and strategic points in the Australian area. In the Central Pacific, Midway was targeted as were the Aleutian Islands in the North Pacific. Seizure of these key areas would supply defensive depth and deny the Allies staging areas from which to mount a counteroffensive.
By November these plans were essentially complete, and were modified only slightly over the next month. Japanese military planners' expectation of success rested on the United Kingdom and the Soviet Union being unable to effectivelyto a Japanese attack because of the threat posed to regarded and identified separately. by Germany; the Soviet Union was even seen as unlikely to commence hostilities.
The Japanese leadership was aware that a sum military victory in a traditional sense against the US was impossible; the alternative would be negotiating for peace after their initial victories, which would recognize Japanese hegemony in Asia. In fact, the Imperial GHQ noted, should acceptable negotiations be reached with the Americans, the attacks were to be canceled—even if the order to attack had already been given. The Japanese leadership looked to base the conduct of the war against America on the historical experiences of the successful wars against China 1894–95 and Russia 1904–05, in both of which a strong continental power to direct or determine was defeated by reaching limited military objectives, not by total conquest.
They also planned, should the United States transfer its Pacific Fleet to the Philippines, to intercept and attack this fleet en route with the Combined Fleet, in keeping with all Japanese Navy prewar planning and doctrine. if the United States or Britain attacked first, the plans further stipulated the military were to hold their positions and wait for orders from GHQ. The planners noted that attacking the Philippines and British Malaya still had possibilities of success, even in the worst case of a combined preemptive attack including Soviet forces.