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Events on Thursday 11 May 1939 1
1939Battles of Khalkhin GolSoviet and Mongolian forces defeat Japan on the Mongolian borderAn undeclared border war between Soviet-Mongolian and Japanese forces ended with a decisive Soviet victory under Georgy Zhukov in late August. A ceasefire took effect on 16 September. The defeat pushed Japan away from war with the Soviet Union and towards expansion southward.