The Battle of Khalkin Gol (also called Nomonhan), sent shockwaves through world history. It was a testbed for future Soviet doctrine and a catalyst for the Japanese political upheaval that brought the United States into every theater of World War II.

A rebuilding Russian army (still reeling from Stalin’s purges) and its combined-arms doctrine faced off against Japan’s modern bushido; the Soviet tactics used successfully here would prove devastating in the war to come. The Russian vi...