And it's not the United States. Here's What You Need To Remember: For all its bluster, Japan had been taught a lesson it would not forget. Or, rather, the tactical lessons would be forgotten five years later, when Japanese soldiers again had to turn themselves into human anti-tank mines in a vain attempt to defeat American Sherman tanks. This is a story of a battle that was and a war that wasn't. Between 1938 and 1939, the Soviet Union and the Japanese Empire fought a series of clashes along the border between Japanese-occupied Manchuria, Russian-controlled Mongolia and the Siberian frontier near Russia's vital Pacific port of Vladivostok.