China fought Japan with aid from the Soviet Union and the United States. After the Japanese attacks on Malaya and Pearl Harbor in 1941, the war merged with other conflicts which are generally categorized under those conflicts of World War II as a major sector known as the China Burma India Theater. Some scholars consider the European War and the Pacific War to be entirely separate, albeit concurrent, wars. Other scholars consider the start of the full-scale Second Sino-Japanese War in 1937 to have been the beginning of World War II. The Second Sino-Japanese War was the largest Asian war in the 20th century. It accounted for the majority of civilian and military casualties in the Pacific War, with between 10 and 25 million Chinese civilians and over 4 million Chinese and Japanese military personnel missing or dying from war-related violence, famine, and other causes." The war has been called "the Asian holocaust."