It is reasonable to say that WWII began, not with the 1939 Nazi invasion of Poland, but with a battle on the outskirts of Beijing in July 1937. After occupying Manchuria in 1931, Japan began a wider invasion of China in 1937. By the end of WWII in 1945, ~13-20 million Chinese people had died. Refugees trying to flee the fighting numbered 100 million. Read this excellent review: History News Network | World War II: From the Chinese Perspective

https://youtu.be/B09IBtlS-2c Unspeakable crimes committed by WWII Japanese medical personnel experimenting on both civilians and prisoners of war have been well documented. Read more about:  Dr. Shiro Oshii and Unit 731  and Japan Confronting Gruesome War Atrocity Unfortunately, unlike modern-day Germany that has openly discussed Nazi atrocities, the current Japanese government appears to offer ambivalent views on the matter and even suggest that some aspects in history textbooks warrant revision.    

This 1942 OSS film provides an excellent overview of Japanese resources at the time. The main points: Japanese farmers and workers are very productive Japan provides 75% of the world's silk the home islands provide adequate food, water (electricity) and forest products coal and oil resources are limited most metals and minerals must come from Japanese possessions in Asia & the Pacific  

  In 1941, the Imperial Japanese Army had a total of 1,700,000 men. At the beginning of WWII most of the Army's divisions were stationed in China and (for fear of Soviet invasion) along the Mongolian border In 1942, soldiers were sent to Hong Kong, the Philippines, Thailand, Burma, the Dutch East Indies and Malaya. By 1945, there were 5.5 million men in the Imperial Japanese Army. Beginning in 1943, largely due to shipping losses, Japanese troops were short of supplies, especially food, medicine, munitions and armaments. Many fighter aircraft become unserviceable for lack of spare parts and many military deaths resulted from illness or starvation. Source: http://en.wikipedia.org/wiki/Imperial_Japanese_Army#World_War_II

With early 20th century industrialization, many poor or unwed Japanese women worked in silk, textile, and weaving factories. Once married, however, women were expected to stop working for wages. Most worked without pay in agriculture. At war from 1937-1945, the lives of Imperial Japanese women were radically changed. Although relegated to various volunteer associations in the early war years, by 1943 the loss of male industrial workers required women to fill their jobs. From age 15, all women who were unmarried and out of school, were required to work. Ultimately, even married women were strongly encouraged to work. In 1944 more than four million Japanese women worked in the industrial fields of aircraft manufacturing, munitions, electrical factories, pharmaceuticals, and textiles.

At war, Japan required large amounts of petroleum, scrap iron, and other raw materials. While 55 percent of its oil came from the USA, Indonesia supplied 25%. After the German occupation of Holland, Japan demanded vital natural resources, especially oil from the Netherlands East Indies. The Indies government stalled negotiations and joined the USA in an embargo on oil and other exports to Japan in the summer of 1941. But after Japanese victories at Singapore and the Battle of the Java Sea, the Netherlands Indies government surrendered on March 9, 1942. Because Dutch colonial rule was resented, many Indonesians were initially in favor of a Greater East Asia Co-Prosperity Sphere with Japan as the focal point. However, the subsequent Japanese occupation proved to be brutal. Military police terrorized civilians, food and other vital necessities were confiscated and ~4 million-Indonesians were forced into manual labor on economic development and defense construction projects. In 1942, rejecting criticism of the "ABCD powers" (America, Britain, China & Dutch), Japan proclaimed itself the leader, protector and  light of Asia.”  (The use of the term "light of Asia" no doubt was chosen to imply high ideals similar to Gautama Buddha as described in the 1879 narrative poem The Light of Asia: The Great Renunciation by Edwin Arnold.    

Front Magazine, Wikimedia Commons  With a format resembling Life magazine, FRONT magazine was created by the Japanese Intelligence Bureau with civilian editors, photographers, and graphic designers to represent the Imperial Japanese empire "in its true form in this time of extreme international change." Published in 15 languages, FRONT focused on the war in Asia with issues featuring the Imperial Navy, the Imperial Army, and Manchuria. Financial support for FRONT came from Mitsui, Mitsubishi, Sumitomo, and other companies that relied on military contracts.  

via Twentieth Century Japanese Art and the Wartime State: Reassessing the Art of Ogawara Shū and Fujita Tsuguharu Similar to the United States, Britain, Germany, Canada, and Australia, the Japanese government and military supported an extensive war art program involving hundreds of artists including: Tsuguharu Foujita.[7] Ryushi Kawabata, 1855–1966.[7] Ryohei Koiso, 1903–1988.[7] Shin Kurihara, 1894–1966.[7] Saburo Miyamoto, 1905–1974.[7] Kenichi Nakamura, 1895–1967.[7] Kita Renzo (1876–1949) Konosuke Tamura, 1903–1986.[7] Kenji Yoshioka, 1906–1990.[7]   In 1951 the United States confiscated one hundred fifty three propaganda battle paintings that had been commissioned by the Japanese Imperial Army, Navy, and Air Force between 1937 and 1945. In 1967 photographer Nakagawa Ichirō  found a collection of War Campaign Record Paintings at Wright-Patterson Air Force Base in Ohio and the  general public was introduced to the paintings once again.   

During the Spanish Civil War, Luftwaffe and Italian Air Force "volunteers," allied with Spanish Fascists, bombed the undefended civilians of Guernica in 1937. During the invasion of Poland in 1939, the Luftwaffe engaged in massive air raids against Polish cities. In addition to the destruction of infrastructure, hospitals were destroyed and many civilians and refugees were killed. In May 1940, the Luftwaffe bombed the center of Rotterdam, killing many civilians. In May 1940, after the Rotterdam attack,  the RAF initiated nighttime bombing raids on German industrial and military targets east of the Rhine. Targeting was so inaccurate however, that the raids soon assumed the character of terror bombing of German villages. During July and August 1940, the Luftwaffe targeted only military airfields and radar stations in Great Britain.  At the time, civilian deaths during Luftwaffe bombing raids against strategic industrial targets were assumed to be collateral damage. On August 24, 1940,  the Luftwaffe, apparently intending to bomb the docks, accidentally dropped bombs on central London, killing nine civilians. On August 25, 1940,  95 RAF aircraft bombed Tempelhof Airport and the Siemens factory near the center of Berlin.  Bombs landed in fields, woods and some residential areas, but  no one was killed. Although the damage was slight, the psychological effect of this first bombing raid on Germany's capitol appeared to have caused Hitler to change tactics. On September 7, 1940, the Luftwaffe initiated the London Blitz, a significant tactical shift in Germany's bombing campaign against Great Britain. Unlike the previous tactical campaign, the Blitz was intended to demoralize the civilian population and force a peace settlement. London, Coventry, Plymouth & Liverpool suffered the most damage during Luftwaffe raids in 1940.  As the war grew, both Axis and Allied bombing campaigns increased and targeting became less restrictive. Bombing cities and civilians was viewed as disrupting enemy war industry, rail and control centers, and breaking the enemy's will to fight. The controversial fire bombings of Hamburg (1943), Dresden (1945), Würzburg and other German cities followed. From September-May 1940 London was bombed 71 times. Berlin was bombed 363 times throughout WWII. Bombing civilians as a means to demoralize the enemy was never successful for either the Luftwaffe or RAF.

Since feudal times, the Empire of Japan had a long tradition of censorship of political discourse. In 1936, the Information and Propaganda Committee issued all official press statements and worked with the Publications Monitoring Department to censor all types of media. The committee issued detailed guidelines to publishers and made (mandatory) suggestions. Any book, magazine, news article or photograph "unfavorable" to the Imperial Army or portraying atrocity (e.g.,Soldiers Alive, Tatsuzō Ishikawa's account of the Nanjing massacre) was prohibited. Writers deemed to promote dissidence were frequently imprisoned. A 1941 revision of the National Mobilization Law eliminated freedom of the press completely. All mail was now subject to scrutiny. In February 1942, all newspapers were ordered to merge, or to cease publication. The Japan Publishers Association agreed to screen all publication drafts before final submission to the official government censors. As the Pacific War situation deteriorated,  the government assumed control of all paper supplies, and permitted use only for official policy issues. In 1944, only 34 magazines were left in publication. In 1945, only one newspaper was permitted per prefecture. read more:   Censorship in the Empire of Japan - Wikipedia, the free encyclopedia.

In 1925 the Imperial Japanese Ministry of Education and the Department of War began to attach military officers to public schools to establish a military training system. In 1931 instruction in budo, the traditional martial arts of Japan,  became compulsory for all students in middle and normal schools.  Students were required to train themselves in either judo or kendo. Budo, the martial way, was intended to promote bushido (samurai spirit), patriotism  and understanding of "the origin of the nation and the dignity of the national constitution."  

   Entartete Kunst was the term used by the Nazis to describe art that was banned on the grounds that it was un-German or Jewish/Bolshevist in nature. "Degenerate" artists were subjected to sanctions, dismissed from teaching positions, forbidden to exhibit or to sell their art, and sometimes forbidden to produce art at all. In 1937, an Entarte Kunst exhibition was staged in Munich by the Nazi regime. In an attempt to turn public opinion against modernism, modernist art was chaotically displayed and mocked. While deriding modernist art, the Nazis promoted traditional painting and sculpture that exalted "Aryan" racial purity, militarism, and obedience to authority. Modern artworks pillaged from museums and private galleries included works by Paul Klee, Marc Chagall and Ernst Kirchner.

    In WWII, bicycles were quiet, flexible transport for thousands of Japanese troops who used them to surprise and confuse defenders. In 1937, 50,000 Japanese bicycle troops participated in the invasion of China. In 1941, the Japanese army rode bicycles through Malaya to capture Singapore. On bicycles, Japanese troops moved faster than retreating Allied Forces. Often spurning main routes, Japanese troops travelled along plantation roads, native paths and over improvised bridges to surprise Allied troops defending the expected roads and river crossings.  

 

  The number of casualties in the Second Sino-Japanese War was shocking: Chinese casualties 3.22 million soldiers 9.13 million civilians killed in crossfire 8.4 million non-military casualties. Chinese sources claim ~35 million total casualties (most Western historians estimate at least 20 million). In addition, the war created 95 million refugees. Japanese casualties Estimated 1.1-1.9 million military casualties, killed, wounded & missing Japan defense ministry claimed only about 200,000, but this is believed to be extremely low considering the length of the conflict Chinese forces claimed 1.77 million Japanese soldiers killed

http://www.youtube.com/watch?v=-QDImDxd0vk Japanese fighters attacked the American gunboat USS Panay at anchor in the Yangtze River outside Nanking on December 12, 1937. Although there was contrary evidence, the Japanese claimed the attack was in error and made reparations. The attack on an American ship that had been evacuating U.S. citizens during the Nanking Massacre resulted in strong condemnation of Japan by the American public. But the American Ambassador Joseph Grew wrote that "never before has the fact that there are 'two Japans' been more clearly emphasized. Ever since the first news of the Panay disaster came, we have been deluged by delegations, visitors, letters, and contributions of money ... trying to express their shame, apologies, and regrets for the action of their own Navy."

Originating with the Anti-Comintern Pact of 1936 (an anti-communist treaty signed by Nazi Germany and Imperial Japan), the Axis alliance was joined by Italy in 1937. In addition, the Axis included Hungary, Romania, Bulgaria, Yugoslavia and various collaborating and/or puppet states of Germany, Italy and Japan.

In January 1937, President Roosevelt directed the Navy Department to proceed with the construction of two replacement battleships, the first such construction since the Washington Naval Treaty of 1922. From 1935 to 1937, the United States Army grew from 118,000 to 158,000 enlisted men. Nevertheless, the isolationist Secretary of War Harry H. Woodring declared that the USA was not keeping up with the large military expansions of other world powers and needed to be further strengthened. Still maintaining a non-intervention foreign policy (unless the Monroe Doctrine was threatened), FDR fired Woodring in 1940 over public disagreement regarding the government's shipment of war materials to Britain.

In the 1937 general elections, with 73% voter participation, the  Constitutional Democratic Party Rikken Minseitō (RMK in the graph) won a slight majority of parliamentary seats over its major rival, the conservative  Friends of Constitutional Government (Rikken Seiyūkai, RSK in the graph). The Constitutional Democratic Party had traditionally promoted equitable distribution of wealth,  protection of personal liberties and opposition to military colonialism in Asia. In the 1937 election, however, the party adopted a more pro-military position.

Wikimedia Commons A rally to boycott Nazi-Germany, held at the third Madison Square Garden on March 15, 1937

In the 1930s Imperial Japanese propaganda promoted the image of a benevolent Big Brother in Asia.

https://youtu.be/VJRwqwJ9eD8 It seems that soldiers don't often talk about their wartime experiences with civilians. And, we know that the Japanese government actively suppressed any opposition to their narrative of events in China. How much did Japanese civilians at home know about the brutal activities of their soldiers in China? The government certainly promoted a whitewashed portrait of the liberation of poor oppressed Chinese by the gallant Imperial Japanese Army. Japan was simply acting as a benevolent "big brother" to bring about a sphere of co-prosperity for East Asia. When Japanese civilians paraded through streets celebrating "glorious victories", did they at some level know what their boys overseas were actually doing? Bitter controversy still exists regarding the actual number of deaths and rapes  the Imperial Army committed in its 1937 rampage of several weeks in Nanking. But, it seems an inescapable fact that a massacre did occur.

At 7:42 A.M. on July 2, 1937 the Coast Guard cutter Itasca, stationed offshore of Howland Island (an uninhabited coral island halfway between Hawaii and Australia) picked up this message: “We must be on you, but we cannot see you. Fuel is running low. Been unable to reach you by radio. We are flying at 1,000 feet.” The ship tried to reply, but the plane seemed not to hear. At 8:45 Earhart reported, “We are running north and south.” Nothing further was heard from Earhart. ______________________ Transmission By RACHEL RICHARDSON JAN. 22, 2016 There was a girl who heard it happen: Amelia Earhart calling on the radio, she and her navigator alternately cursing and defining their position by latitude, as best they could read it in the bellowing wind, and by what they could surmise of their rate per hour, last land they’d seen. Stay with me, someone, and the girl wrote each word in her composition book, kept the channel tuned, hunched to the receiver when static overtook the line. Why do I think of her? The coast guard laughed at her father holding out the schoolgirl scrawl and sent him home ashamed. A lost woman is a lost woman, he told her, and the sea is dark and wide.    

Since the invasion of Manchuria and the creation of the puppet state Manchukuo in 1931, an uneasy truce existed between Japan and China. The Marco Polo Bridge, linking Beijing to Chinese-controlled areas in the south, became the flashpoint for renewed warfare between the Imperial Japanese and nationalist Chinese armies. Whether this "incident" that provoked full-scale war was intentional or a pretext for the invasion of China is a matter of historical debate. Nevertheless, the agenda of right wing Japanese proponents of expansion  ("Asia for the Asians") was advanced.  

http://www.youtube.com/watch?v=F54rqDh2mWA The 30-year era of sublime optimism and confidence regarding passenger zeppelins came to an abrupt and tragic end in May 1937 with the fiery crash of the German airship Hindenburg. 13 passengers, 22 crew members and one person on the ground perished.