One U.S. response was the decision to send large amounts of arms and equipment to China, along with a military mission to advise on their use. The underlying strategy was to revitalize China’s war effort as a deterrent to Japanese land and naval operations southward. The Nationalist army was ill-equipped to fight the Japanese in 1941. Its arsenals were so lacking in nonferrous metals and explosives that they could not produce effectively. The maintenance of millions of ill-trained and under-equipped troops was a heavy drain on the economy. There was no possibility that the United States could arm such numbers from its limited stocks while building up its own forces and assisting many other countries. In addition, there was a formidable logistics problem in shipping supplies along the 715-mile (1,150-km) Burma Road, which extended from Kunming to Lashio, the terminus in Burma of the railway and highway leading to Rangoon.

By December 1941 the United States had sent a military mission to China and had implicitly agreed to create a modern Chinese air force, maintain an efficient line of communications into China, and arm 30 divisions. Japan’s bombing of Pearl Harbor in Hawaii brought the United States into alliance with China, and Great Britain joined the Pacific war as its colonial possessions were attacked. This widening of the Sino-Japanese conflict lifted Chinese morale, but its other early effects were harmful. With the Japanese conquest of Hong Kong on December 25, China lost its air link to the outside world and one of its principal routes for smuggling supplies. By the end of May 1942, the Japanese held most of Burma, having defeated the British, Indian, Burmese, and Chinese defenders. China was almost completely blockaded. For the moment, there was little China’s allies could do other than state a willingness to offer China loans.

The solution was found in an air route from Assam, India, to Kunming, in southwest China—the dangerous “Hump” route along the southern edge of the Himalayas. In March 1942 the China National Aviation Corporation (CNAC) began freight service over the Hump, and the United States began a transport program the next month. But shortages and other difficulties had to be overcome, and not until December 1943 were cargo planes able to carry as much tonnage as was carried along the Burma Road by trucks two years earlier. This was much less than China’s needs for gasoline and military equipment and supplies.

Conflicts within the international alliance

China’s alliance with the United States and Great Britain was marked by deep conflict. Great Britain gave highest priority to the defeat of its main enemy, Germany. The U.S. Navy in the Pacific had been seriously weakened by the Japanese air attack at Pearl Harbor and required many months to rebuild. During the winter of 1941–42, the grand strategy of the United States and Great Britain called for the defeat of Germany first and then an assault across the Pacific against Japan’s island empire. China was relegated to a low position in U.S. strategic planning. The United States aimed to keep China in the war and enable it to play a positive role in the final defeat of Japan on the continent. Chiang Kai-shek, on the other hand, envisaged a joint strategy by the United States, the British Commonwealth, and China over the whole Pacific area, with China playing a major role. He demanded an equal voice in Allied war planning, which he never received, though U.S. Pres. Franklin D. Roosevelt was generally solicitous. From the fundamentally different outlooks of Chiang, British Prime Minister Winston Churchill, and Roosevelt and because of the divergent national interests of China, the British Commonwealth, and the United States, there followed many controversies that had powerful repercussions in China and led to frustrations and suspicions among the partners.

After Burma fell to the Japanese, a controversy developed over whether the principal Chinese and U.S. effort against Japan should be devoted to building up U.S. air power based in China or to reform of the Chinese army and its training and equipment for a combat role. Chiang advocated primary reliance on U.S. air power to defeat Japan. Several high-ranking U.S. generals, on the other hand, emphasized creation of a compact and modernized Chinese ground force able to protect the airfields in China and to assist in opening an overland supply route across northern Burma. Already in India, the United States was training two Chinese divisions from remnants of the Burma campaign, plus artillery and engineering regiments (this became known as X-Force). Also in training were Chinese instructors to help retrain other divisions in China. Both air development and army modernizing were being pushed in early 1943, with a training center created near Kunming to reenergize and reequip select Chinese divisions (called Y-Force), and a network of airfields was being built in southern China. This dual approach caused repeated conflict over the allocation of scarce airlift space.

By the end of 1943 the China-based U.S. Fourteenth Air Force had achieved tactical parity with the Japanese over central China, was beginning to bomb Yangtze shipping, and had conducted a successful raid on Japanese airfields on Taiwan. A second training center had been started at Guilin to improve 30 more Chinese divisions (Z-Force). The campaign to open a land route across northern Burma had run into serious difficulty. At the first Cairo Conference in November, Chiang met Churchill and Roosevelt for the first time. The Cairo Declaration issued there promised that, following the war, Manchuria, Taiwan, and the Pescadores Islands would be returned to China and that Korea would gain independence. The three allies pledged themselves to “persevere in the…prolonged operations necessary to procure the unconditional surrender of Japan.” These words, however, concealed deep differences over global strategy. U.S. planners realized that Japan might be approached successfully through the south and central Pacific and that the Soviet Union would enter the war against Japan after Germany’s defeat; hence, the importance of China to U.S. grand strategy declined. Churchill was unwilling to use naval resources, needed for the forthcoming European invasion, in a seaborne invasion of Burma to help reopen China’s supply line. Yet Chiang had demanded a naval invasion of Burma as a condition to committing the Y-Force to assist in opening his supply line. Shortly after Cairo, Churchill and Roosevelt agreed to set aside the seaborne invasion of Burma; when Chiang learned of this, he requested enormous amounts of money, supplies, and air support, asserting that otherwise Japan might succeed in eliminating China from the war. The United States did not accede, and Chinese-American relations began to cool.

Phase three: approaching crisis (1944–45)

China was in crisis in 1944. Japan faced increasing pressure in the Pacific and threats to its supply bases and communications lines in China as well as to nearby shipping. Its response was twofold—first, to attack from Burma toward Assam to cut the supply lines or capture the airfields at the western end of the Hump and, second, to capture the railway system in China from north to south and seize the eastern China airfields used by the United States.

The British and Indian army defeated the Japanese attack on Assam (March–July 1944) with help from transport planes withdrawn from the Hump. But the Japanese campaign in China, known as Ichigo, showed up the weakness, inefficiency, and poor command of the Chinese armies after nearly seven years of war. During April and May the Japanese cleared the Beiping-Hankou railway between the Huang He and the Yangtze. Chinese armies nominally numbering several hundred thousand troops were unable to put up effective resistance. Farmers and laborers in Henan attacked the collapsing Chinese armies—only recently their oppressors.

The second phase of the Ichigo campaign was a Japanese drive southward from Hankou and northwestward from Guangzhou to take Guilin and open the communication line to the India-China border. By November the Chinese had lost Guilin, Liuzhou, and Nanning, and the Japanese were approaching Guiyang on the route to Chongqing and Kunming. This was the high-water mark of Japan’s war in China. Thereafter, it withdrew experienced divisions for the defense of its overextended empire, and China finally began to benefit from the well-trained X-Force when two divisions were flown in from Burma in December to defend Kunming.

Meanwhile, the Chinese government was involved in a crisis of relations with the United States, which contended that the Chinese army must be reformed, particularly in its command structure, and that lend-lease supplies must be used more effectively. There were also many subsidiary problems. Gen. Joseph Stilwell, the executor of disagreeable U.S. policies in China, had developed an unconcealed disdain for Chiang, whom he nominally served as chief of staff. Stilwell was an effective troop commander, and Roosevelt requested that Chiang place Stilwell in command of all Chinese forces. In the context of Chinese politics, in which control of armies was the main source of power, President Chiang’s compliance was virtually inconceivable. He declined the request and asked for Stilwell’s recall. Roosevelt agreed, but thereafter his relations with Chiang were no longer cordial. Stilwell was replaced by Gen. Albert Coady Wedemeyer.