The obscure battle of Nomonhan would have remained unknown to me had not Haruki Murakami made Nomonhan a toxic background to his masterpiece, The Wind-Up Bird Chronicle. I knew that during World War II Japan had attacked the United States but not Russia. Thanks to Murakami, I now know one reason why.
In 1931, the expanding Japanese Empire occupied Manchuria, establishing the puppet state of Manchukuo. Border clashes between Manchukuo and the Soviet satellite state of Mongolia flared and intensified until August, 1939 when a superior Soviet force decimated a Japanese division at Nomonhan. The consequences for the future were profound. To begin with, Japan signed a non-aggression pact with Stalin, ultimately sparing the Soviet Union from having to defend two fronts during World War II. After having been so thoroughly spanked by Russian tanks at Nomonhan, Japan honored its pact even after Hitler breached the separate German-Soviet non-aggression pact (negotiated while the battle of Nomonhan was being waged) by invading the Soviet Union in June, 1941. So much for the Japan-German alliance. It’s an open question whether the Soviet Union would have survived fighting on two fronts. At the very least had Japan opened a second front, a drastically weaker Soviet Union would have emerged from World War II, significantly thawing the Cold War. What’s more, following Nomanhan, Japan altered its game plan, heightening the likelihood of a collision with the United States. Elements in the Japanese military favoring a Northern strike and the ultimate conquest of portions of Siberia were discredited while advocates of a Southern strike toward the poorly defended Southeast Asian colonies of France, Britain, and the Netherlands prevailed. The rest as they say is history.