In practice, U.S. forces were usually overseen by General Joseph Stilwell, the Deputy Allied Commander in China; the term "CBI" was significant in logistical, material and personnel matters; it was and is commonly used within the US for these theaters.

Western powers had exploited China through the open door policy, advocated by United States diplomat William Woodville Rockhill, while Japan intervened more directly, creating the puppet-state of Manchukuo.

The infamous Rape of Nanking galvanized Western opinion and led to direct financial aid for the Kuomintang (Nationalists) and increasing economic sanctions against Japan.

Japan responded with a tightly co-ordinated offensive on 7/8 December, simultaneously attacking Pearl Harbor, the Philippines, Malaya, Singapore, Hong Kong, Guam, Wake Island, and Thailand.

China could be supplied only by flying over the Himalaya mountains ("The Hump") from India,[2] or capturing territory in Burma and building a new road—the Ledo Road.

The British, primarily concerned with India, looked to Burma as the main theater of action against Japan and wanted Chinese troops to fight there.

[5][6] "On April 14, 1942, William Donovan, as Coordinator of Information (forerunner of the Office of Strategic Services), activated Detachment 101 for action behind enemy lines in Burma.

The first unit of its kind, the Detachment was charged with gathering intelligence, harassing the Japanese through guerrilla actions, identifying targets for the Army Air Force to bomb, and rescuing downed Allied airmen.

"[7] Detachment 101's efforts opened the way for Stilwell's Chinese forces, Wingate's Raiders, Merrill's Marauders, and the counter-attack against the Japanese Imperial life-line.

When the GALAHAD force (later to become the 5307th Composite Unit (Provisional)) arrived in Bombay in October 1943, it came under the British-led South East Asia Command (SEAC) and Admiral Lord Mountbatten.

[12] Although Stilwell was the control and co-ordinating point for all command activity in the theater, his assumption of personal direction of the advance of the Chinese Ledo forces into north Burma in late 1943 meant that he was often out of touch with both his own headquarters and with the overall situation.

The 11th Army Group was redesignated Allied Land Forces South East Asia (ALFSEA), and NCAC was decisively placed under this formation.

Relations improved even further after new U.S. military aid began arriving, together with capable USAAF officers such as Brigadier General William D. Old of CBI Troop Carrier Command,[16] and Colonels Philip Cochran and John R. Alison of the 1st Air Commando Group.

Although the India-China Division of the AAF's Air Transport Command received its tonnage allocations from Stratemeyer as Stilwell's deputy, ICD reported directly to Headquarters ATC in Washington, D.C.

In August 1944, Admiral Mountbatten said to a press conference that EAC fighter missions had practically swept the Japanese air force from Burmese skies.

[19] This achievement considerably reduced dangers to Air Transport Command cargo planes flying in support of the Hump airlift operation.

By May 1944, EAC resupply missions in support of the Allied ground offensive had carried 70,000 tons of supplies and transported a total of 93,000 men, including 25,500 casualties evacuated from the battle areas.