Canton Operation
The Canton Operation was part of a campaign by Japan during the Second Sino-Japanese War to blockade China to prevent it from communicating with the outside world and importing needed arms and materials. Control of Guangzhou and the Pearl River Delta would provide a base to make the blockade of Guangdong province more effective by seizing southern China's major port and isolate the British port of Hong Kong.
Background
By the end of 1937, south China was crucial to the Republic of China as a means of maintaining contact with the outside world. Guangzhou and Hongkong served as vital centers of transportation and international aid to Chiang Kai-Shek. Approximately 80 percent of supplies from abroad to the Chinese forces in the interior passed through Guangzhou. Imperial General Headquarters believed that a blockade of Guangdong province would deprive China of essential war material and the ability to prolong the war.In 1936 the Hankow-Canton railway was completed. With the Kowloon-Canton railway, this formed a rapid all-rail link from south China to central and northern China. For the first sixteen months of the war about 60,000 tons of goods transited per month through the port of Hong Kong. The central government also reported the import of 1.5 million gallons of gasoline through Hong Kong in 1938. More than 700,000 tons of goods would eventually reach Hankou using the new railway.
For comparison, the Soviet Union was more willing to provide direct military support to prolong the war. In addition to the Sino-Soviet Non-Aggression Pact signed in August 1937, a barter agreement was negotiated to trade munitions for strategic materials such as tungsten and antimony. Starting in 1937 Soviet war material was transported through Xinjiang to Lanzhou using 20,000 camels. Chinese raw materials would travel back the same way or via Hong Kong to Vladivostok. By 1940, 50,000 camels and hundreds of trucks were transporting 2,000-3,000 tons of Soviet war material per month into China.
Japanese planning for operations began in early November 1937. The objectives of the blockade could be achieved by seizing a portion of Daya Bay and conducting air operations from there. In December 1937, the 5th Army with the 11th Division, the Formosa Mixed Brigade and the 4th Air Brigade were activated in Formosa under the command Lt. Gen. Motoo Furusho to accomplish this objective. Due to the proximity of Daya Bay to Hongkong, the Japanese Government feared that trouble might break out between Britain and Japan. The operation was subsequently suspended and the 5th Army was deactivated. By June 1938, the Battle of Wuhan caused the Imperial General Headquarters to realize that it could not localize the fighting. Imperial General Headquarters reversed policy and began preparations to capture Guangzhou and expedite the settlement of the war.
Prelude
4th War Area Army
The 4th War Area Army under the command of He Yingqin in 1938 was assigned to the defense of south China. General Yu Hanmou was in command of the 12th Army Group defending Guangdong province. Eight divisions and two brigades of regular army troops were deployed in the vicinity of Guangzhou. Another five divisions of regular army troops were deployed in Fujian province. The 4th War Area Army totalled about 110,000 regular army troops. Most regular army units in Guangxi province and four divisions from Guangdong had been transferred north to participate in the Battle of Wuhan.In addition to regular army troops, two militia divisions were deployed in the vicinity of Guangzhou and the Guanxi militia consisted of five militia divisions in Guangxi province. The militia divisions would generally be recruited from the local civilian population and disbanded as the army moved through new areas. These divisions were generally employed for security, supply transportation and reconnaissance.
The main strength of the Chinese forces in Guangdong were concentrated in Guangzhou and to the immediate east of the city. Other elements defended Chaozhou and western Guangdong. Chinese defensive installations included the Humen fortress overlooking the mouth of the Pearl River and three defensive lines near Daya Bay. Three batteries of four three-inch guns, a battery of three 120mm guns and Soviet 37mm guns were stationed in Guangzhou for anti-air defense.
Japanese Blockade
Prior to the Canton Operation, the Imperial Japanese Navy conducted an aerial and naval interdiction campaign against China's communication lines to neighbouring regions. Japan believed that the blockade would hasten the end of the war. Disruption of the Chinese logistics network was the primary Japanese objective in Guangdong province from August 1937 until October 1938.The 5th Fleet's 10th Division blockaded and patrolled the coast from Haimenchen, Zhejiang to Shantou and the 5th Destroyer Squadron patrolled the coast south of Shantou. Occasionally Japanese units from the Marianas were deployed in support of coastal blockade operations in south China. These usually consisted of cruisers accompanied by a flotilla of destroyers. One or two aircraft carriers and fleet auxiliaries would also be on station. Naval interdictions focused on stopping junks ferrying military supplies from Hong Kong to coastal China. The first recorded attack occurred in September 1937 when eleven junks were sunk by a Japanese submarine. Although the Japanese were able to blockade Chinese shipping and ports, foreign shipping could still enter and depart from Hong Kong. The central government had setup Hong Kong as a warehouse for munitions and supplies to pass through.
Aerial interdictions directed bombers against Chinese railway bridges and trains in Guangdong. Starting from October 1937, the Japanese launched air raids against the Sunning railway. The attacks targeted government facilities and bridges in Jiangmen and towns along the railway. By 1938, airstrikes against the Kowloon-Canton railway became a common occurrence with damaged trains found periodically along the railway. An air defense early warning system was established to shunt trains during air raids into forested areas that provided overhead concealment. In May 1938 the Colonial Office and the Foreign Office approved a Chinese request to construct and operate a locomotive repair yard within the New Territories to keep the railway operational. Airstrikes conducted against rail facilities in Guangzhou were designed to interrupt rail supplies from Hong Kong so that Japan would not be required to commit to land operations in south China. However, the air raids had failed to severely impede railway operations or stop supplies moving through Hunan or Guangxi.
The blockade in south China also included attacks against aircraft flying out of Hong Kong. In November 1937, a Royal Navy aircraft from HMS Eagle encountered Japanese naval anti-aircraft fire off the coast of Hong Kong. In December 1937, fifteen Japanese bombers overflew Lantau Island and the Taikoo docks. In August 1938 Japanese naval aircraft shot down a China National Aviation Corporation passenger plane and another two passenger planes from the Eurasia Aviation Corporation were shot down the following month.
In addition to airstrikes against military targets, the Japanese conducted politically motivated terror bombing in Guangzhou. Bombing of Guangzhou intensified starting from May to June 1938 with the employment of incendiary munitions and low-level strafing attacks against ships. The IJN air service operating from bases in Taiwan and the aircraft carrier Kaga conducted about 400 airstrikes during this period and continued into July. By the end of summer only 600,000 of the original 1.3 million residents remained in the city of Guangzhou. From August 1937 to October 1938 casualties in Guangzhou were estimated at 6,000 killed and 8,000 injured.