Battle of Zaoyang–Yichang

The Japanese were seeking a quicker solution to achieve a Chinese surrender. The Japanese contemplated moving directly down the Yangtze to the relocated Chinese capital, Chongqing. To do so, they would need to capture a critical town in western Hubei province, Yichang.

The Japanese attack did not commit many troops or material, which enabled the main Chinese commander, Li Zongren, who had frustrated the Japanese before, to repel the Japanese.

On 1 May 1940, three divisions of the IJA 11th Army under command of General Waichiro Sonobe began a drive towards Zaoyang. They pushed towards the 5th warzone's strongholds in the Tongbaishan and Dahongshan mountains, attempting to encircle and destroy the Chinese 31st Army Group under General Tang Enbo in a pincer movement. The Chinese strategy aimed to let the Japanese forces run low on supplies, and then counterattack, as had been successfully employed at the Battle of Changsha. When the Japanese managed to outmaneuver Tang's forces, General Zhang Zizhong marched to his aid with the Chinese 33rd Army Group. The Japanese forces rallied and pushed back the Chinese, and General Zhang Zizhong was cut down in a burst of machine gun fire when he refused to retreat from the front lines. He was the most senior Chinese commander to be killed in combat during the war.^[4]

After defeating Zhang Zizhong's 33rd army group, the 11th army launched a general offensive against the fourteen to fifteen Chinese divisions gathered around Zaoyang on May 19. The 75th corps and 56th division of the 39th corps suffered very heavy casualties and retreated to the west bank of the Tangbai River.^[5] At dusk on May 20, the 233rd infantry regiment of the 39th division sent three officers to scout ahead for the crossing point of the Tangbai River. Two of the scouts laid prone on the ground and used telescopes to observe the situation on the other side. The third scout stood upright as incoming gunfire was light and believed that the land they were observing was a sandbar. However, the report from the other two scouts, who judged that it was the opposite bank of the river, was accepted. At midnight on the 21st, the regiment began to land on what was believed to be the other side of the river. As soon as a green signal was fired to indicate a successful crossing, the defending 4th security regiment of Hubei Province led by Li Langxing (李朗星), which had been lying in wait, opened fire all at once. As the sandbar offered no cover, the regiment quickly suffered heavy losses. More than 300 including regimental commander Tetsujirō Kanzaki (神崎哲次郎) were killed in action. The Tangbai River crossing became known as the 39th division's most tragic battle.^[6][7]

The Japanese used chemical weapons against Chinese forces who lacked chemical weapons in order to compensate for when they were numerically inferior, whenever Chinese were defeating the Japanese in hand-to-hand combat. The Japanese did not dare to use gas against the Americans because the Americans had their own chemical weapons stockpile and the Japanese feared retaliation.^[8][9][10]

The Japanese launched gas attacks against Chinese when the Chinese were defeating and overwhelming the Japanese in hand-to-hand combat, like at the battle of Yichang in 1941, where Japanese ground forces in the city were routed by Chinese soldiers but the Japanese deployed mustard gas to win the battle.^{[11][12][13][14][15]}

According to Japanese records, the Japanese casualties were 2,700 troops killed and 7,800 wounded. Chinese records show that 11,000 Japanese troops were killed. The Japanese 3rd Division received 6,044 additional soldiers in July 1940.^[21][22] According to the history of the 65th Infantry Regiment of the Japanese 13th Division, the regiment had 280 combat deaths in this battle.^[23] The 2nd Independent Mountain Artillery Regiment received 1,330 additional soldiers from July 15, 1940 until March 15, 1941, to supplement the combat losses in the Battle of South Guangxi, Battle of Zaoyang-Yichang, and the Battle of South Henan and non-combat losses from the start of this battle until February 1941.^[24]

While the Chinese 5th War Area arguably made tactically sound decisions in its battle plans, it was ultimately overwhelmed by the sheer firepower of the Japanese combined arms offensive, relying primarily on small arms to face the onslaught of Japanese air, naval, artillery, and armoured striking power. As the Chinese commanders had surmised, the Japanese forces were overextended, and were not in a position to pursue their victory. However, the Imperial Japanese Navy pushed strongly for the occupation of Yichang, located at the edge of Sichuan and connecting the 5th and 9th war zones. The Navy felt that it was critically needed as a forward base for air attacks against Chongqing. After considerable argument, the Japanese Army agreed to occupy Yichang.^[4] This dealt a considerable blow to the morale and fighting capacity of the Chinese as no large-scale offensive was mounted after this operation.^[25]

• Order of Battle: Battle of Zaoyang-Yichang