Khalkhin Gol — the First Clash

The border between Mongolia, an ally of the USSR, and Manchukuo, Japan's puppet state, is poorly demarcated along the Khalkhin Gol river. Tokyo and Moscow keep wary troops there. On 11 May 1939, Mongol horsemen cross the river near Nomonhan to graze their beasts; the Manchukuoan guards drive them back. The incident, banal in appearance, sets the powder alight.

The Kwantung Army, an elite Japanese force stationed in Manchuria, cultivates a notorious autonomy from Tokyo: its officers have, in the past, provoked faits accomplis that the government has had to ratify. Its commanders see in the incident the opportunity to teach the Soviets a lesson and to assert the firmness of the border.

But the escalation is dangerous. The USSR has considerable armoured and aerial means in the Far East, and Japan is already bogged down in the war in China. Should it respond with a show of force, contain the affair locally, or refer it to Tokyo, which preaches prudence? Everything will depend on the scale the local commanders will wish — or be able — to give their riposte, far from Tokyo's gaze.