Mongolia 1939

The Khalkha River winds from north to south near the tip of a flat, grassy salient of Mongolia that juts about 100 miles eastward into Manchuria. In the 1930s, Manchuria’s Japanese overlords regarded the river as an international boundary line: Manchuria to its east, and Outer Mongolia—then a protectorate of the Soviet Union known as the Mongolian People’s Republic—to the west. Those on the Mongolian side of the border claimed that line ran some 10 miles east of the river, near the tiny hamlet of Nomonhan. While the precise location of the border meant little to the nomadic Mongols who had followed their herds back and forth across the river for centuries, the Kwantung Army, the elite Japanese force that controlled Manchuria, took a different view.