The Rising Sun – Japan’s Road to War (1937

Introduction to the Rising Sun

Across East Asia, the rise of Imperial Japan reshaped the strategic landscape in the years leading up to World War 2, long before the wider world understood how far its ambitions would reach. The years from 1937 to 1941 marked a period in which Japan’s power, confidence, and territorial reach expanded dramatically — an era defined by the rising sun of an increasingly assertive empire. Having already seized Manchuria in 1931, Japan entered this period determined to dominate the region and secure the resources it deemed essential for national survival and imperial destiny. The spark came in July 1937 at the Marco Polo Bridge, where a brief clash between Japanese and Chinese troops escalated into full-scale war. From that moment, Japanese forces advanced deep into China, capturing major cities such as Beijing, Shanghai, and Nanjing. What Japan expected to be a short, decisive campaign instead became a prolonged, brutal struggle, marked by atrocities and unrelenting resistance. Unable to force China to capitulate, Tokyo broadened its strategy, looking beyond China’s borders for leverage, resources, and strategic advantage. By 1940, Japan moved into northern French Indochina with the agreement of Vichy France, extending its reach into Southeast Asia and tightening the blockade on China. The following year, Japanese forces advanced into southern Indochina, bringing them to the doorstep of British Malaya, the Dutch East Indies, and the Philippines. These moves alarmed Western powers and triggered a series of escalating economic sanctions. The United States responded with embargoes on aviation fuel, metal, and eventually oil — a measure that placed Japan in a desperate strategic bind. By mid-1941, Japan faced a stark choice: retreat from its expansionist path or secure vital resources by force. Talks with Washington continued, but trust had evaporated. Within Japan’s military leadership, the conviction grew that the empire must strike quickly, before American military power could make resistance impossible. A pre-emptive blow — one that would disable the US Pacific Fleet — became increasingly seen as the only viable course. As 1941 drew to a close, Japan’s rise had reached its decisive moment. The imperial sun that had climbed steadily since the early 1930s now prepared to push the entire Asia-Pacific into war. The decisions made in these years paved the way for the coordinated assaults of December 1941, transforming regional tensions into a global conflict.

Map showing Japanese expansion in East Asia and the Pacific from 1931 to 1939, including advances into China and clashes with the Soviet Union — Map illustrating Japanese territorial expansion and military advances in East Asia from 1931 to 1939, including operations in China, border clashes with the Soviet Union at Nomonhan, and control of Pacific mandate islands.

1937

2nd February 1937

Admiral Osami Nagano is appointed Commander-in-Chief of the Imperial Japanese Navy’s Combined Fleet, placing him in command of Japan’s principal operational naval force as tensions in East Asia continue to rise.

1st June 1937

Prince Fumimaro Konoe becomes Japanese Prime Minister.

7th July 1937

Full-scale war between China and Japan breaks out following weeks of tension due to Japanese military presence in northern China. The catalyst is the Marco Polo Bridge Incident, where Japanese and Chinese troops exchange fire near the town of Wanping, southwest of Beiping (now Beijing). The confrontation begins when a Japanese soldier is reported missing during a night training exercise near the historic bridge, prompting Japanese troops to demand entry into Wanping to search for him. The Chinese garrison refuses, leading to an escalating exchange of gunfire that quickly develops into full hostilities.

13th August 1937

The Battle of Shanghai begins as Japanese and Chinese forces clash across the city, marking one of the earliest and most intense urban battles of the Sino-Japanese War.

1st September 1937

The Battle of Taiyuan opens in northern China as Japanese forces push into Shanxi Province, confronting Chinese armies defending the approaches to the regional capital.

9th November 1937

Japanese forces capture Shanghai after nearly three months of heavy fighting, forcing Chinese troops to withdraw from the city. Japan secures victory in the Battle of Taiyuan, completing its advance through Shanxi Province.

Emperor Hirohito on horseback reviewing Japanese troops during a military inspection, 1937 — Emperor Hirohito reviews Japanese troops during a military inspection in 1937, as Japan’s armed forces expand amid the escalating conflict in China.

26th November 1937

The Battle of Shanghai formally ends with a Japanese victory, consolidating their control of the city and freeing forces for continued operations along the Yangtze River.

8th December 1937

Japan proclaims the establishment of Mengjiang, a puppet state in Inner Mongolia, installing pro-Japanese Mongol leaders to administer the region under military supervision.

Major G.T. Wards

United Kingdom Assistant Military Attaché in Tokyo

15th December 1937

‘The Japanese Army as it is to-day is a formidable force.’

1938

6th March 1938

Japanese troops reach the Yellow River in northern China, advancing their front after months of fighting across Shanxi and Henan Provinces.

29th July 1938

The Soviet–Japanese border conflict escalates as the Battle of Lake Khasan begins, with Japanese and Soviet forces clashing along the disputed frontier near Vladivostok.

Fumimaro Konoe

Prime Minister of Imperial Japan

3rd November 1938

‘Japan’s mission in East Asia is to establish a new order based on justice.’

1939

11th May 1939

The Battle of Khalkhin Gol begins as Japanese and Manchukuoan troops clash with Soviet and Mongolian forces along the disputed Manchukuo–Mongolia border. Initial fighting erupts when a Japanese detachment crosses the Khalkhin Gol (Khalkha River), triggering a wider confrontation that will grow into the largest and most decisive border battle between the two powers.

Japanese infantry advancing during the Battle of Khalkhin Gol, 1939, with wrecked Soviet armored vehicles in the background — Japanese infantry advance across open steppe terrain during the Battle of Khalkhin Gol in 1939, as fighting intensifies between Japanese and Soviet forces along the Manchukuo–Mongolia border.

14th June 1939

The Tientsin Incident unfolds when Japanese authorities impose a blockade on the British concession in Tientsin, North China, sealing off road and river access and demanding the handover of four Chinese suspects sheltered inside. The blockade sharply escalates tensions with Britain and highlights Japan’s tightening control over the foreign concessions in North China.

26th July 1939

The United States formally notifies Japan that it is terminating the 1911 U.S.–Japan Commercial Treaty, giving six months’ notice. The decision, driven by Japan’s ongoing war in China, ends Japan’s preferential trade status and signals a hardening of American policy toward Tokyo.

1940

12th June 1940

Thailand and Japan sign a non-aggression pact, easing tensions along their shared frontier and giving Japan diplomatic leverage in Southeast Asia as it consolidates its position following early victories in China.

22nd September 1940

The Vichy French government grants Japan permission to station troops in northern French Indochina. Japanese forces enter the territory the same day, securing airfields and transit routes that place additional pressure on China’s supply lines.

26th September 1940

The United States imposes an embargo on scrap iron and steel exports to Japan, targeting key materials used in Japanese industry and war production. The move reflects growing American alarm at Japan’s expansion into Southeast Asia.

27th September 1940

In Berlin, Japan signs the Tripartite Pact with Germany and Italy. The agreement establishes a defensive alliance pledging mutual support if any signatory is attacked by a nation not already involved in the European or Sino-Japanese conflicts—an implicit warning aimed at deterring the United States. Tokyo presents the pact as part of a “new order” in Europe and East Asia.

5th October 1940

Japanese Prime Minister Prince Fumimaro Konoe warns that continued American hostility toward the Axis could lead to war, reflecting rising tensions as U.S. embargoes begin to bite and Japan tightens its grip on Indochina.

8th October 1940

The United States government advises all American citizens in the Far East to leave, citing increased instability and the growing risk posed by Japan’s military actions in China and Indochina.

18th October 1940

Britain reopens the Burma Road, restoring a vital supply route to China after a three-month closure agreed to under Japanese pressure. The reopening strengthens Chinese resistance at a moment when Japan seeks to sever all remaining lines of support.

Yōsuke Matsuoka

Japanese Foreign Minister

13th April 1941

‘Japan will advance southward to establish the Greater East Asia Co-Prosperity Sphere.’

1941

13th April 1941

Japan signs a non-aggression pact with the Soviet Union in Moscow, guaranteeing neutrality between the two nations and allowing Japan to redirect its strategic focus toward Southeast Asia.

17th June 1941

Japanese–Dutch negotiations collapse after Japan demands expanded economic rights and access to resources in the Dutch East Indies. The failure pushes Japan closer to taking the territory by force.

27th June 1941

Japan reaffirms the “Greater East Asia Co-Prosperity Sphere,” presenting its expanding dominance in East and Southeast Asia as a regional partnership while tightening political and economic control over occupied territories.

24th July 1941

Vichy France agrees to allow Japanese forces to occupy military bases in southern French Indochina, granting Japan naval and air positions that threaten British Malaya, Singapore, and the Dutch East Indies.

25th July 1941

The United States, United Kingdom, and Dominions freeze all Japanese assets, sharply restricting Japan’s ability to purchase oil and other critical materials abroad.

28th July 1941

Japanese troops enter and occupy southern French Indochina, consolidating control with Vichy cooperation. In response, Japan freezes American, British, and Dutch assets in retaliation.

6th September 1941

Japan’s Imperial Conference resolves that the nation will go to war against the United States and the European colonial powers of Southeast Asia unless negotiations succeed quickly. Military preparations accelerate as diplomatic options narrow.

Imperial Japanese Navy aircraft carriers in heavy seas, 1941 — Imperial Japanese Navy Aircraft Carriers ploughing through heavy seas in November 1941, as Japan’s carrier strike force prepares for major operations across the Pacific.

Order of the Blue Sky and White Sun - Nationalist China

Manchuria Dispatch Badge awarded by Imperial Japan to personnel dispatched to Manchuria during the early 1930s

Soviet Medal ‘For the Victory over Japan’ - Soviet Union

China Incident War Medal awarded by Imperial Japan for military service during the Second Sino-Japanese War