The United States and China were allies during World War II and more than 250,000 Americans served in what was known as the China-Burma-India Theater. In this photograph, a U.S. sergeant and a lieutenant, both members of the Y-Force Operations Staff, demonstrate methods of disarming the enemy with a bayonet to Chinese soldiers.
China Burma India Theater (CBI) was the United States military designation during World War II for the China and Southeast Asian or India–Burma (IBT) theaters.
Operational command of Allied forces (including U.S. forces) in the CBI was officially the responsibility of the Supreme Commanders for South East Asia or China.
However, US forces in practice 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.
