The Battles of Khalkhin Gol (Russian: Бои на Халхин-Голе; Mongolian: Халхын голын байлдаан) were the decisive engagements of the undeclared Soviet–Japanese border conflicts involving the Soviet Union, Mongolia, Japan and Manchukuo in 1939. The conflict was named after the river Khalkhin Gol, which passes through the battlefield. In Japan, the decisive battle of the conflict is known as the Nomonhan Incident (Japanese: ノモンハン事件, Hepburn: Nomonhan jiken) after Nomonhan Burd Obo, an obo,[27] a cairn set as a border marker in the Yongzheng period of the Qing dynasty. The battles resulted in the defeat of the Japanese Sixth Army.
