The Second Sino-Japanese War, also known as the Sino-Japanese War, War of Resistance Against Japan, Japan-China War, Second China-Japan War, 1937–1945 War, or Anti-Japanese War, was a defining conflict in World War II Asia. Fought from July 7, 1937, to September 2, 1945, it pitted Chiang Kai-shek’s Nationalist Chinese forces and Mao Zedong’s Chinese Communist Party against the Imperial Japanese Army, driven by Japanese militarism. This Sino-Japanese conflict shaped Chinese military history, marked by Chinese resistance and brutal Japanese occupation of China. This article explores the timeline, locations, causes, course, casualties, and outcome of the 1937–1945 conflict, highlighting its role in the Pacific War and Asian theater of WWII.
Time and Date of the Battle
The Second Sino-Japanese War spanned from July 7, 1937, to September 2, 1945. It began with the Marco Polo Bridge Incident on July 7, 1937, near Beijing, and ended with Japan’s surrender following the atomic bombings of Hiroshima and Nagasaki. Key engagements included the Battle of Shanghai (August 13–November 26, 1937), Battle of Nanjing (December 1937), and Battle of Wuhan (June–October 1938). The war overlapped with the Chinese Civil War and merged into the broader Pacific War after Japan’s attack on Pearl Harbor in December 1941, concluding with Japan’s formal surrender on September 2, 1945.
Location of the Battle
The Second Sino-Japanese War unfolded across vast regions of China, from the Yangtze River Delta to northern plains, Manchuria, and the China-Burma-India Theater. Major battlegrounds included:
- Shanghai, China: The Battle of Shanghai raged in the Yangtze River Delta, a key economic hub.
- Nanjing: The capital, site of the Battle of Nanjing and Nanjing Massacre.
- Wuhan: A central Chinese city, critical in the Battle of Wuhan.
- Manchuria: Japan’s initial invasion point post-Mukden Incident (1931), leading to Manchukuo.
- Northern and Central China: Areas like Taiyuan, Battle of Changsha, and Henan saw prolonged fighting.
- China-Burma-India Theater: Allied efforts supported Chinese forces via the Burma Road.
The war’s geographic scope strained Japanese military campaigns while enabling Chinese guerrilla warfare in rural areas.
Causes of the Conflict
The Second Sino-Japanese War stemmed from Japanese imperialism and China’s internal divisions, escalating earlier tensions:
- Japanese Aggression in China: The 1931 Mukden Incident enabled Japan to occupy Manchuria, establishing Manchukuo. Under leaders like Hideki Tojo, Japan sought to dominate East Asia, viewing China as a resource-rich target for Japanese militarism.
- Marco Polo Bridge Incident: On July 7, 1937, a skirmish near Beijing’s Marco Polo Bridge, sparked by a missing Japanese soldier, escalated into full-scale war. Japan demanded concessions, which Chiang Kai-shek rejected, igniting the Sino-Japanese conflict.
- Chinese United Front: The 1936 Xi’an Incident forced Chiang Kai-shek to ally with Mao Zedong’s Chinese Communist Party, forming the Second United Front to bolster Chinese Nationalist resistance against Japan.
- Chinese Internal Divisions: The Chinese Civil War (1927–1937, paused during WWII) weakened China’s ability to resist Japanese invasion of China, but the Anti-Japanese resistance unified disparate factions.
- Global Context: Japan’s withdrawal from the League of Nations (1933) after the Mukden Incident and its rejection of the Treaty of Shimonoseki’s constraints emboldened Japanese occupation policies, setting the stage for the Asian WWII battles.
These factors fueled Sino-Japanese tensions, making war inevitable.
Course of the Battle
The Second Sino-Japanese War unfolded in three phases: early Japanese advances (1937–1938), a stalemate with Chinese guerrilla warfare (1939–1941), and integration into the Pacific War (1941–1945). It involved urban battles, rural resistance, and Allied support.
Phase 1: Japanese Advances (1937–1938)
The war began with the Marco Polo Bridge Incident (July 7, 1937), followed by Japan’s capture of Beijing and Tianjin. The Battle of Shanghai (August 13–November 26, 1937), led by Iwane Matsui for Japan and Chiang Kai-shek for China, saw 300,000–700,000 Nationalist Chinese forces face 80,000 Imperial Japanese Army troops. Despite fierce Chinese resistance, Japan captured Shanghai, with the Sihang Warehouse defense symbolizing defiance. The Battle of Nanjing (December 1937) followed, resulting in the Nanjing Massacre, where 40,000–300,000 civilians and soldiers were killed. The Battle of Wuhan (June–October 1938) saw Japan capture another key city, but China’s scorched-earth tactics and flooding of the Yangtze slowed Japanese progress.
Phase 2: Stalemate and Guerrilla Warfare (1939–1941)
By 1939, Japan controlled eastern China but faced overstretched supply lines. The Chinese Communist Party, under Mao Zedong, launched Chinese guerrilla warfare in rural areas, disrupting Japanese occupation policies. The Nationalist Chinese Army defended Changsha (1939, 1941) and other strongholds, forcing Japan into a costly war of attrition. The Chinese united front coordinated urban and rural resistance, while Japan’s Ichigō Offensive (1940) aimed to crush Chinese morale but failed to break the stalemate.
Phase 3: Pacific War Integration (1941–1945)
Japan’s attack on Pearl Harbor (December 1941) merged the Sino-Japanese War into the Pacific War. Allied support via the China-Burma-India Theater, including the Burma Road and U.S. Flying Tigers, bolstered Chinese military tactics. The Battle of Changsha (1942) and Operation Ichigō (1944) saw mixed results, with Japan capturing territory but suffering heavy losses. By 1945, Chinese resistance, combined with Allied offensives and the atomic bombings, forced Japan’s surrender on September 2, 1945.
Strategic Dynamics
The Imperial Japanese Army leveraged superior technology, air power, and naval support, but Japanese military campaigns struggled with China’s vast terrain and population. Chiang Kai-shek’s defensive strategy and Mao Zedong’s guerrilla tactics prolonged the war, while Japanese occupation policies, including forced labor and massacres, fueled Anti-Japanese resistance.
Casualties
The Second Sino-Japanese War was catastrophic, with estimates from historical records:
- Chinese Forces and Civilians: Approximately 3–4 million military deaths (including Nationalist Chinese Army and Chinese Communist Party forces) and 10–20 million civilian deaths, totaling 14–24 million casualties. The Nanjing Massacre alone killed 40,000–300,000. Disease, starvation, and air raids in the Yangtze River Delta and other regions contributed heavily.
- Imperial Japanese Army: Around 1.5–2.5 million military deaths, including 400,000–500,000 in combat and the rest from disease and wounds. Japanese losses were significant in battles like Shanghai and Wuhan.
- Allied Forces: In the China-Burma-India Theater, Allied troops (U.S., British, Indian) suffered ~20,000 casualties.
The Nanjing atrocities and widespread destruction underscored the war’s brutality, impacting China’s WWII role.
Who Won the Second Sino-Japanese War?
The Allies, including China’s Nationalist Chinese forces and Chinese Communist Party, won the Second Sino-Japanese War, with Japan’s surrender on September 2, 1945. The Chinese united front, supported by U.S. and Allied forces in the Pacific War, outlasted Japanese imperialism. The victory ended Japanese occupation of China, but China’s heavy losses and the resumption of the Chinese Civil War (1945–1949) limited its immediate gains. Chiang Kai-shek’s Nationalists and Mao Zedong’s Communists both claimed credit, though the latter gained political momentum. The war’s end reshaped East Asia, with Japan’s defeat formalized in the Potsdam Declaration.
Conclusion
The Second Sino-Japanese War (1937–1945) was a brutal 1930s-1940s warfare chapter in World War II Asia, driven by Japanese aggression in China and countered by Chinese Nationalist resistance and Chinese guerrilla warfare. From the Marco Polo Bridge Incident to the Nanjing Massacre and Battle of Wuhan, Chiang Kai-shek and Mao Zedong’s forces resisted Iwane Matsui and Hideki Tojo’s Imperial Japanese Army across the Yangtze River Delta and beyond. With 14–24 million Chinese and 1.5–2.5 million Japanese casualties, the Anti-Japanese War showcased Chinese military history’s resilience.
The Allied victory in 1945 ended Japanese occupation policies but reignited the Chinese Civil War, shaping Sino-Japanese tensions and Asian WWII battles. The war’s legacy underscores China’s WWII role as a cornerstone of the Pacific War and global anti-fascist struggle.
Sources: Mitter, Forgotten Ally: China’s World War II; Harmsen, Shanghai 1937: Stalingrad on the Yangtze; Peattie et al., The Battle for China; National WWII Museum; Drea, Japan’s Imperial Army
