'Beta' (iv) was a US and Chinese partially realised plan to follow 'Alpha' with an offensive designed first to take Kweilin and Liuchow, and then to drive to the coast at Hong Kong and Canton, with Chinese and US forces in southern China (August/September 1945).

The object of the plan was thus to recapture from the occupation forces of General Naozaburo Okabe’s Japanese 6^th Area Army those regions which had been seized by the Japanese forces in 'Ichi' between April 1944 and May 1945, and thus drive a land wedge between the Japanese forces in northern China and those in the extreme south of China and also in South-East Asia (Burma, Malaya, Thailand and Indo-China) at a time when the disruption of Japan’s maritime lines of communications by the US Navy’s submarine and air forces was almost total. This would have effectively isolated the Japanese forces in the mainland regions of the 'Southern Resources Area' from any possibility of reinforcement and supply from the home islands.

The 6^th Area Army had been created on 25 August 1944 within Field Marshal Shunroku Hata’s (from 23 November 1944 General Yasuji Okamura’s) China Expeditionary Army primarily as a military reserve and garrison force for the continued Japanese occupation of the central provinces of China between the Yangtze and Yellow rivers. After the success of 'Ichi', many of the area army’s more experienced formations and units were transferred from China to more active fronts in the Pacific War, a move which left the 6^th Area Army to hold the gains in central China. The 6^th Area Army was demobilised after the surrender of Japan on 15 August 1945 at Hankou (part of modern Wuhan) in China, without ever seeing any degree of major combat.

The Japanese 'Ichi' offensive in eastern China had ended early in December 1944 after the Japanese forces had occupied the whole of the railway network areas of Changsha, Liuchow and Tuhshan and of Hengyang and Canton, as well as Nanning and the road to the Indo-China border. The resulting Japanese threat to Kunming and Chungking and to the road connecting them through Kweiyang had led Lieutenant General Albert C. Wedemeyer, commander of the US forces in China and chief-of-staff to Generalissimo Chiang Kai-shek, to develop the 'Alpha' plan to concentrate the 34 most reliable Chinese divisions in the area bounded by Kweiyang, Tuhshan, Poseh, Mengtzu and Kunming as a means of covering the possible Japanese axes of advance toward Kunming. As the Chinese land forces were of poor quality, training and equipment, and as it would be a lengthy process to reorganise, retain and re-equip them, Wedemeyer had obtained permission from the Combined Chiefs-of-Staff to bring the 'Alpha' force up to a total of 36 divisions by transferring two of the US-trained Chinese divisions from Burma, on whose northern front they had been operating, and also to transfer the US 'Mars' Force, to provide US personnel to train and advise the Chinese divisions.

The fact that the Japanese made no further efforts early in 1945 to advance into Kweichow province enabled Wedemeyer to consider another plan, which he designated as 'Beta' (iv), for a two-part offensive by August or September 1945: this 'Beta' (iv) envisaged the recapture of Kweilin and Liuchow as its first phase, and a port (Canton and/or Hong Kong) on the Chinese coast as its second phase. This plan was accepted in principle by Chiang, who informed Admiral the Lord Louis Mountbatten, heading the South-East Asia Command, in March that he hoped to prepare 13 armies, each of three divisions, for the purpose. Of these 39 divisions, 11 were to be found from the Yunnan armies and another five from the SEAC front, the latter including the remaining three US-trained Chinese divisions. Thus the implementation of 'Beta' (iv) would mean that all Chinese assistance towards the recapture of Burma would end, a fact which Mountbatten and the Combined Chiefs-of-Staff felt they could accept by the end of March as a result of the success of Lieutenant General Sir William Slim’s British 14^th Army in central Burma. It was therefore agreed that the remaining three Chinese divisions would be transferred to China during June 1945.

While Wedemeyer was preparing his plans to defend the area of Kweiyang and Kunming, and considering the 'Beta' (iv) offensive later in the year, the Japanese policy in China was radically altered. On 23 November 1944 Okamura, who had been commander of North China Area Army and 6^th Area Army, was elevated to command of the China Expeditionary Army responsible for all Japanese operations in China. The new commander-in-chief submitted plans to Imperial General Headquarters for an offensive to be launched in March 1945 from Hengyang and Liuchow to the west in order to capture Chihkiang (a US air base) and Kweiyang respectively, followed by an advance on Chungking (the Chinese Nationalist capital) and Chengtu (another US air base). Okamura believed that a success of this magnitude might end the war in China and topple the Nationalist regime.

Imperial General Headquarters was doubtful whether or not, given the Japanese manpower and matériel available, such an offensive into the province of Szechwan would obtain success, especially as it appeared that the course of the war in Europe was strengthening the will of Chiang’s Nationalist régime to continue fighting. Moreover, the Japanese high command felt that there was the risk that Okamura’s proposed offensive might hinder the improvement of the defences in the strategic areas around Japan now threatened by the US forces advancing through the Pacific in the direction of the home islands. The high command accordingly refused to countenance major operations deep in China. In January 1945 the Imperial High Command therefore instructed Okamura that the primary task of the China Expeditionary Army was to concentrate the bulk of its strength in the coastal region of southern and central China, especially along the lower reaches of the Yangtze river, to defeat any US invasion. Okamura was also ordered to make every effort to neutralise USAAF strength in China be means of raids, and to encompass the defeat of Chiang’s régime by political rather than by military means. For these tasks the China Expeditionary Army was to be reorganised and reinforced by 230,000 men despatched from Japan to increase its strength by 25% to about one million men organised as 30 infantry divisions, one tank division, 20 independent mixed brigades, 11 independent infantry brigades, 13 independent garrison units and one cavalry brigade. Even so, the capability of the China Expeditionary Army was not really formidable as a result of its poor standards training and lack of adequate equipment.

Okamura made Lieutenant General Hisaichi Tanaka’s 23^rd Army responsible for south-eastern China in the area round Canton, Lieutenant General Sajishige Nagatsu’s 13^th Army for the lower reaches of the Yangtze river, and Lieutenant General Sadamu Shinomura’s North China Area Army for the coast in the vicinity of Tsingtao. Okabe’s 6^th Area Army was to hold the existing occupied areas in central China and also to attempt the destruction of the Chinese armies in that area. Following the loss of its airfields in eastern China during 1944, the USAAF had started to build large numbers of airfields in Yunnan, Kweichow, Hunan and Szechwan provinces, and had increased its attacks on river shipping, airfields and railways in north-eastern China, so Okamura decided to destroy the air bases at Laohokow and Chihkiang: the operation to destroy the first was entrusted to Lieutenant General Eitaro Uchiyama’s (from 7 April Lieutenant General Takashi Takamori’s) 12^th Army of the North China Area Army and that of the destruction of the latter to Lieutenant General Kazuyoshi Banzai’s 20^th Army of the 6^th Area Army.

The Japanese advance on Laohokow began on 12 March and the airfields in the vicinity had been taken without difficulty by 8 April. The attempt to occupy Chihkiang began on 15 April but met with considerable resistance from the Chinese armies concentrated by Wedemeyer to the east of Kweiyang, reinforced by the two US-trained Chinese divisions from Burma, hurriedly flown forward from Kunming. The Japanese offensive was halted in the mountainous area some 50 miles (80 km) short of its objective and, as the Chinese armies started to make enveloping attacks on both flanks, the 20^th Army began to pull back to its starting position, to the west of Hengyang, on 9 May.

As a result of changing relations with the USSR, the Imperial General Headquarters decided early in May to reinforce General Kenkichi Ueda’s Kwantung Army in Manchukuo and Lieutenant General Yoshio Uetsuki’s 17^th Area Army in Korea from the China Expeditionary Army. Okamura was accordingly instructed to send an army headquarters and three divisions from the North China Area Army and one division of the 6^th Area Army to Korea and Manchuria in June, to evacuate the areas it held along the railways linking Hankow with Canton and Hengyang with Tuhshan in Hunan, Kwangsi and Kiangsi provinces, and to concentrate his forces around Canton, in the area of Hankow and Wuchang, and in northern China. On 26 May the Japanese evacuated their forces from Nanning, with the result that overland communications with their forces in Indo-China became impossible. In the next three months the Japanese also left Liuchow, Kweilin and Hengyang in that order, the formations which had been holding them moving north to increase the strength of the China Expeditionary Army in northern China. The 23^rd Army, halved to just three divisions, was left in south-eastern China to hold the Liuchow peninsula, the area of Hong Kong and Canton, and Swatow. When the Japanese surrendered in the middle of August, Liuchow and Kweilin had been evacuated and the 6^th Area Army was withdrawing rapidly through Hengyang toward Hankow.

The first draft of the 'Beta' (iv) plan was submitted to Chiang on 14 February 1945. The plan was based on the assumptions that the war against Germany would end in May, that operations in the Pacific would continue along their planned routes and force the Japanese in China to redeploy their forces to the north and east to meet the possibility of US landings along the Chinese coast, that the 4-in (101.6-mm) oil pipeline from Myitkyina under construction alongside the Ledo Road would reach Kunming on 15 July and that the Ledo Road and the air ferry route from India would together deliver 80,000 tons per month. The plan’s objectives were to exploit the anticipated increase in the delivery of supplies to China to improve the military situation in that country, to aid operations in the Pacific and to open a sea port on the Chinese coast so that the Chinese theatre could take a more active role in the destruction of the Japanese forces in China. The plan had four phases: the first was the capture of the area of Liuchow and Nanning from about 1 May; the second was the consolidation of the captured area; the third was the concentration of the forces needed for an advance to the area of Canton and Hong Kong; and the fourth was the offensive to capture that area. Wedemeyer proposed in the third phase to capture Fort Bayard (now Zhanjiang at the south-western end of Guangdong province) at the northern end of the Liuchow peninsula and to establish a coastal base at the port so that supplies for China could be brought in by ship to augment those brought overland or by air from India. Major General Claire L. Chennault’s US 14^th Army Air Force was to subordinate all but the maintenance of local air superiority to the task of isolating the Japanese forces in southern China from their bases in northern and central China.

The plan’s feasibility depended largely on two things: on the ability of the air ferry and Ledo Road combination to deliver supplies from India sufficient for the equipment of 34 Chinese divisions in time for their full training, and on the transfer of the Chinese training establishments at Ramgarh in India and the three remaining US-trained divisions from India to China by way of the Ledo Road, thus raising to 39 the number of Chinese divisions with US training. The plan also depended on the presence of an adequate number of transport aircraft within China to move the Chinese forces eastward to their concentration areas and to maintain them in the forward areas, since land communications within southern China were poor and it was impossible to deliver the number of motor vehicles needed in China by way of the Ledo Road. It was assumed that extra transport aircraft would become available shortly after the defeat of Germany, and that this would allow an increase in the monthly delivery to China from India from 43,000 tons in March to some 62,000 tons from May to August, of which some 85% would be needed for 'Beta' (iv).

In April Wedemeyer flew to Washington to explain his plan and its logistical requirements to the Joint Chiefs-of-Staff, who gave their approval on 20 April. While in the USA Wedemeyer was given a guidance paper on US policy toward China, a paper which was subject to revision in the light of later developments. It stated that the short-term objective in China was the unification of all Chinese resources for the war against Japan, while the long-term objective was to help develop 'a united, democratically progressive and cooperative China'.

The loss of Laohokow early in April had little effect on Wedemeyer’s plan, although the Japanese occupation of the airfields in that area rendered the task of US 14^th AAF more difficult. To defeat the Japanese offensive against Chihkiang, which had to be held since its loss would interfere seriously with the first and second phases of 'Beta' (iv), Wedemeyer was compelled to take aircraft from the 'over the Hump' transport role to move the two US-trained divisions already in China to the battle area and to supply the Chinese armies involved. The operations were eventually successful but they severely upset the training programme of the Chinese divisions for 'Beta' (iv). Other factors which also delayed the preparations for 'Beta' (iv) were the fact that the number of motor vehicles arriving from India along the Ledo Road was less than had been expected as a result of the difficulty of finding reliable drivers, the poor condition of roads within China and the delays caused by monsoon destruction of or damage to bridges, the non-arrival of the additional transport aircraft in the numbers expected; and the growth in China of the number of Americans, all of whom had to be fully maintained by air. All these factors combined to reduce the percentage of the monthly deliveries available for equipping the Chinese divisions from 52 in January 1945 to 25 in August.

As far as Wedemeyer was concerned, the situation was improved by the Japanese withdrawal of their forces from southern China, a process which began toward the end of May. The offensive to capture the area of Nanning and Liuchow (the first phase of 'Beta' [iv]) thus became unnecessary and all that was required of the Chinese armies was to follow the retreating Japanese and exert as much pressure as possible on them. In this circumstance Wedemeyer revised 'Beta' (iv) in June. Having occupied the area of Nanning, Liuchow and Kweilin without fighting, he now prepared to use it as a base for the attack on the area of Canton and Hong Kong in the last quarter of 1945. He proposed to use four Chinese divisions, supplied by air from the airfields at Liuchow and at Tanchu after their capture, to take Fort Bayard on 1 August, and then on 1 September to move to the east and occupy suitable concentration areas for the assault on Canton, which was to begin on 1 November. To supply the forces for the November offensive, the Joint Chiefs-of-Staff agreed that after the capture of Fort Bayard five Liberty ships a month would be allocated to transport packaged petrol, oil and lubricants, vehicles, ammunition, steel airstrip matting, food and tents, and that an airlift would be organised to carry 15,000 tons of mixed supplies to the airfields at Tanchu, Liuchow and Kweilin. This would supplement an airlift of 15,000 tons per month forward from Kunming, and thereby give a total of 30,000 tons per month in the forward area, which would be sufficient to maintain the Chinese armies and enable them to take offensive action both to the north in the direction of Hengyang and to the east in the direction of Canton.

To support these offensives, Major General Howard C. Davidson’s (from 19 August Major General Albert F. Hegenberger’s) US 10^th AAF was brought forward from India to Kunming in July 1945 and with Chennault’s (from 10 August Major General Charles B. Stone’s) US 14^th AAF placed under the overall command of Lieutenant General George E. Stratemeyer. To increase the flow of supplies required from India to support the additional air strength in China, two new airfields were hurriedly built in India (one in Bengal and the other in Assam), the airfields at Kharagpur near Calcutta originally built for the Boeing B-29 Superfortress heavy bombers of the XX Bomber Command were handed to the US Air Transport Command and a new airfield was built at Bhamo in Burma to supplement the Myitkyina group of airfields.

Chinese troops had meanwhile occupied Ishan and Liuchow on 10 June and 1 July respectively, but did not capture Tanchu and its associated airfield until 5 August. This delayed the attack on Fort Bayard, although the Chinese troops advancing from Nanning were within 20 miles (32 km) of the port by 3 August.

With the US 'Silverplate' and 'Centerboard' atomic bombings of Hiroshima and Nagasaki, and the Soviet entry into the war with the launch of its 'Avgust Buri' campaign to take Manchuria and Inner Mongolia, it seemed probable that Japan would surrender, so Wedemeyer was instructed on 12 August to halt the advance.