Often overlooked in the history of the Second World War is the American contribution to the China-Burma-India Theater. While some of America’s fiercest battles took place against Japanese defenders in the Pacific, it is important to understand that throughout the war, the majority of Japan’s fighting force was tied down in China—thanks in no small part to the support of the United States.
The Empire of Japan invaded China in 1937. China was already on the verge of a civil war between Generalissimo Chiang Kai-shek’s Nationalist faction and Mao Zedong’s Communists, and the rushing tide of Japanese invaders overwhelmed both their armies. Nevertheless, they fought back desperately and the Japanese offensive bogged down into a long campaign of attrition.
The Chinese war effort was dependent on a steady stream of Allied supplies coming into the country through India, Burma, and French Indochina (Vietnam). Japan moved to cut those supply lines during its campaigns, occupying Indochina in 1941. Even before the United States went to war with Japan, President Franklin Roosevelt supported the Chinese Nationalists in their fight, though he could not directly interfere. The American Volunteer Group was formed; known as the “Flying Tigers,” this band of American fighter pilots was recruited to serve with Chinese forces under the leadership of the American flyer Claire Chennault. Famous for the fearsome shark mouths they painted on the noses of their P-40 Warhawk fighters, the Flying Tigers operated out of China and Burma to keep the supply lines clear. Though they were constantly outnumbered and the Japanese Zero fighter vastly outclassed their antiquated P-40s, the Flying Tigers scored an impressive combat record against the superior Imperial Japanese Air Force.
In December 1941, the Western Allies faced a tenacious new enemy in the East when Imperial Japan finally declared war on Britain and the United States. In the following months, Japanese armies swept across the Far East and Pacific Ocean, seizing key Allied holdings: the Philippines, America’s westernmost bastion; Singapore, the center of British power in Southeast Asia; Hong Kong, Burma, the oil-rich Dutch East Indies—all fell under the banner of the Rising Sun. As Allied armies conducted a hasty retreat into India, Roosevelt sent an emissary, Lieutenant General Joseph Stillwell, to aid the beleaguered Chinese still holding out in the east.
Roosevelt recognized the value of keeping the Chinese front open and active. When the war in the Pacific broke out, the Japanese still had six hundred eighty thousand troops in China, more than in all the other theaters combined. As long as the Chinese continued to fight, the Japanese would be forced to keep troops in the theater that might otherwise be sent elsewhere in the Pacific Theater. But the Japanese were aware of this, as well; when Japanese forces took Burma and threatened Northern India, the Burma Road—the last route into China—was closed.
While the Allies regrouped, efforts turned to supplying the Chinese. With the Burma Road out of action, the only way to get supplies in was to fly them in from India. American transport pilots called it flying the “Hump” route, as the dangerous path took them over the high Himalaya Mountains. Moving supplies over the Hump was incredibly inefficient—for every four tons of gasoline flown into China, three and a half tons were required to transport it there. Still, the stubborn continuous effort yielded results, reaching an average of twenty thousand tons of supplies transported per month by the war’s end.
In late 1942, as Americans pushed west across the Pacific, the United States shifted its China strategy—new emphasis was placed on the expansion of American air power in Asia. At Chennault’s urging, it was decided that American bombers based in China could bomb the Japanese islands and bring Japan to its knees. The majority of supplies flying in over the Hump were diverted to Chennault’s bombers, and airfields sprung up all over China. These bases rightly concerned the Japanese, and one of the primary objectives of their massive Ichigo Offensive in 1944 was to destroy them.
In 1944, the Allies moved to retake Northern Burma and construct the new Ledo Road into China. It was during this offensive that the American 5307th Composite Unit (known as Merrill’s Marauders, after commander Brigadier General Frank Merrill) entered combat. Inspired by the British “Chindit” guerilla unit, these American troops operated deep behind the Japanese lines in the Burmese jungle to create chaos and confusion. These indomitable fighters pushed hard into the Japanese flank, notably seizing and holding the Myitkyina airfield in May 1944, which was the main Japanese air base in Northern Burma and directly in the path of the Ledo Road. Unfortunately, the Marauder’s Burmese campaign took a heavy toll on its men; perpetually outnumbered and devastated by tropical diseases like dysentery, malaria, and typhus, Merrill’s Marauders was dissolved after the Myitkyina offensive when only a few hundred men could still bear arms.
By 1945, China’s military significance had greatly faded in the eyes of American strategists. They had lost confidence in Chiang Kai-shek and his Nationalist faction; Japan’s Ichigo Offensive in 1944 had ravaged Nationalist forces. Furthermore, thirteen American airfields were lost. In the Pacific, Americans had captured Saipan, Guam, and Tinian in the Marianas—airfields on these isolated islands were closer to Japan, safe from attack, and far easier to supply.
Nevertheless, the Allies had successfully pushed the Japanese out of Northern Burma, completing the Ledo Road and reopening the land route into China in January 1945. Before long, Japanese armies were falling back in Southern Burma and China, while American armies in the Pacific tightened the noose on the Home Islands. Though they would continue to fight fiercely, the war was all but over for the Empire of Japan.
The China-Burma-India Theater