The Battle of Khalkhin Gol begins

On 11 May 1939, on the steppe by the Khalkhin Gol river on the eastern edge of the Mongolian People’s Republic, Mongolian border guards clashed with the cavalry of Manchukuo. The dispute concerned a strip of land some twenty kilometres wide between the river and the small mound of Nomonhan-Burd-Obo. Within a few days regular troops, Japanese and Soviet, had appeared on both sides, and a skirmish between a few dozen horsemen had turned into a four-month undeclared war. The Japanese called it the “Nomonhan incident” (Nomonhan jiken), the Russians the “battles on the Khalkhin Gol”, and the Mongols simply a war. It ended in September 1939 with the destruction of a Japanese division, and it changed the way Tokyo looked at war with the Soviet Union.

The disputed steppe

The border between Khalkha – today’s Mongolia – and Barga, the steppe country around Lakes Hulun and Buir Nur, had been laid down in 1734 by the authorities of the Qing Empire. It ran along a low ridge about twenty kilometres east of the Khalkhin Gol, and one of its markers was the very mound of Nomonhan-Burd-Obo. For the nomads who grazed their herds there, the administrative boundary meant little. The problem arose when, after the Mukden incident, Japan seized Manchuria and in 1932 created the puppet state of Manchukuo, into which Hulunbuir was incorporated. The Japanese, relying among other things on a Russian map of 1906, held that the border followed the riverbed. Mongolia, a people’s republic wholly dependent on Moscow since 1924, kept to the eighteenth-century line. In 1935 the two sides held talks on demarcation in the border town of Manzhouli, but after several rounds they broke down.

The quarrel over a seemingly worthless stretch of steppe had strategic significance. For the Japanese, Mongolia was a Soviet wedge driven between Manchukuo and Mengjiang, from which the railway running west out of Manchuria could be threatened. For the Soviet Union it was the forward approach to Lake Baikal and the Trans-Siberian Railway. On 12 March 1936 the USSR and Mongolia signed a protocol of mutual assistance, under which the Soviet 57th Special Corps was stationed in the country from 1937. At the same time Moscow imposed its own Great Purge on Mongolia: in 1937–1939 thousands of people were arrested and executed, including most of the former leaders, officers and many lamas, accused of spying for Japan. Power was concentrated in the hands of Marshal Khorloogiin Choibalsan, the executor of Stalin’s will.

Border incidents between Mongolia and Manchukuo had occurred since 1935. Some ended in an exchange of fire, others in battles involving armoured cars and aircraft. In July and August 1938 the Japanese Korean Army fought two weeks of battles with the Red Army at Lake Khasan, at the other end of the border. They ended in a truce, but in the Kwantung Army, which occupied Manchukuo, the view was that Tokyo had shown weakness.

Tsuji’s principles

In April 1939 the commander of the Kwantung Army, General Kenkichi Ueda, sent his subordinate units the “Principles for the Settlement of Border Disputes between Manchukuo and the USSR”. They had been written by Major Masanobu Tsuji, the army staff’s ambitious and ruthless operations officer. The document laid down that where the border was not clearly demarcated, the line was to be determined “on his own” by the local defence commander, and that in the event of a clash he was to act so as to win “regardless of the strength of the forces and the course of the border”. It was even permissible to enter the enemy’s territory temporarily. The Kwantung Army assumed that a resolute blow would deter the Soviets from provocations more effectively than concessions. The General Staff in Tokyo received the text but took no position on it.

On the Khalkhin Gol sector, responsibility for applying these principles lay with the 23rd Infantry Division, based at Hailar, some two hundred kilometres from Nomonhan. It was a unit formed in 1938, made up largely of reservists, more lightly armed than the standing divisions and untrained; it had spent the winter of 1938/1939 mainly getting its men used to the frost. Its commander, Lieutenant General Michitarō Komatsubara, was a former military attaché in Moscow and was regarded as an expert on the Red Army. Alongside it at Hailar were stationed Manchukuo cavalry units, made up mainly of local Barga Mongols.

11 May

The course of the first clash is known in two mutually exclusive versions. According to Japanese sources, on which the American historian Alvin D. Coox relied, a detachment of Mongolian cavalry some 70–90 strong crossed the Khalkhin Gol in search of water and pasture for their horses and entered the disputed strip on the eastern bank. Manchukuo cavalry attacked the Mongols and drove them back across the river. According to the Soviet and Mongolian version, it was a Japanese–Manchukuo cavalry detachment of up to three hundred men with machine guns that intruded into Mongolian territory and attacked the Mongolian border post at Nomonhan-Burd-Obo, and was then repulsed when reinforcements arrived. Japanese authors acknowledge that at the time both sides reported the same thing – “the enemy intruded, we inflicted losses on him and drove him back” – and that the truth cannot now be established. Nor was this the first shooting in the area: according to Mongolian data, as early as January 1939 Japanese soldiers near Nomonhan had fired on and abducted Mongolian border guards, and on the night of 7–8 May there had been an exchange of fire over an island in the river.

On 12 May the Mongols returned in greater strength. On 13 May a telegram from the 23rd Division reached Kwantung Army headquarters in Xinjing: since the morning of the previous day some seven hundred “Outer Mongolian” troops had crossed the river west of Nomonhan and were fighting Manchukuo forces. Komatsubara announced that he would destroy the enemy with part of his division and the whole Manchukuo garrison of Hailar, and asked for motor vehicles and reconnaissance aircraft. Tsuji and his fellow staff officers claimed years later that none of them had known the name “Nomonhan” at the time and that they had had to look for it on the map. Some Japanese historians doubt this: within two hours the staff had assigned the division more aircraft and transport than it had asked for.

The first weeks

Komatsubara sent to the river a force under Lieutenant Colonel Yaozō Azuma: the divisional reconnaissance unit, two infantry companies and Manchukuo cavalry. When the force arrived on 15 May the Mongols had already gone from the eastern bank, and Azuma turned back to Hailar. That same day Japanese light bombers assigned to support him flew not only across the line Mongolia regarded as the border but across the river itself, and bombed Mongolian yurts on the western bank, killing and wounding somewhere between a dozen and several dozen people.

The Soviet side reacted faster than the Japanese expected. The commander of the 57th Special Corps, Komdiv Nikolai Feklenko, sent to the Khalkhin Gol a force of motorised infantry, armoured cars and artillery, which was joined by the Mongolian 6th Cavalry Division. The Soviets bridged the river and occupied the hills on the eastern bank. Komatsubara, ignoring the Kwantung Army’s advice to wait for the time being, dispatched a larger group to the river under Colonel Takemitsu Yamagata: a battalion of the 64th Infantry Regiment, Azuma’s detachment once again, and Manchukuo cavalry – more than 2,000 men in all. He estimated the enemy at a few hundred men with a handful of tanks. In reality there were some 2,300 Soviet and Mongolian troops on the other side, with several dozen armoured cars and artillery on the high western bank.

On 28 May the Japanese attacked, aiming to encircle the enemy on the eastern bank and cut him off from the crossing. Azuma’s detachment broke through to the rear of the Soviet positions, but the rest of the group stalled, and the detachment, cut off from communications, was surrounded and for two days shelled by artillery and attacked by infantry, armoured cars and flamethrower tanks. On 29 May the last survivors launched a counter-attack; Azuma was killed. According to Japanese figures, 159 Japanese soldiers fell in the May fighting, 105 of them from Azuma’s detachment, while Soviet losses amounted to 138 killed and missing and 198 wounded, in addition to Mongolian dead, among them the commander of the 6th Cavalry Division. Both sides withdrew from the battlefield, and both claimed victory.

At the same time an air war flared over the steppe. Japanese pilots flying Nakajima Ki-27 fighters shot down more than a dozen Soviet aircraft in the first engagements at the end of May, for the loss of one. On 29 May Moscow sent to Mongolia a group of experienced airmen, veterans of Spain and China, led by the deputy commander of the Red Army Air Force, Yakov Smushkevich.

Moscow and Tokyo

The fighting on the Khalkhin Gol began just as both states were reorienting their policies. In Moscow, on 3 May 1939, Maxim Litvinov was replaced as People’s Commissar for Foreign Affairs by Vyacheslav Molotov, and the USSR was simultaneously conducting talks on an alliance with Britain and France, begun with the Soviet proposal of April, and cautiously sounding out Germany. On 31 May Molotov declared in the Supreme Soviet that the USSR would defend the borders of Mongolia as it would its own. In Tokyo the government had been headed since January 1939 by Kiichirō Hiranuma, and the War Minister, Seishirō Itagaki, was pressing for the Anti-Comintern Pact to be turned into a military alliance with Germany and Italy. The General Staff wanted to limit the conflict, since the army was tied down by the war in China, but the Kwantung Army was acting more and more on its own initiative.

Stalin took the May setbacks seriously. At the beginning of June Komdiv Georgy Zhukov, deputy commander of the Belorussian Special Military District, arrived in Mongolia on an inspection. His reports on the poor leadership of the corps led to his replacing Feklenko on 12 June. Zhukov moved the headquarters closer to the front and began bringing up tanks, artillery and lorries from railheads hundreds of kilometres away. The Japanese escalated too: on 27 June the Kwantung Army’s air force, without Tokyo’s consent, bombed Soviet airfields deep inside Mongolia, and at the beginning of July Komatsubara forced a crossing of the Khalkhin Gol. In the fighting for Mount Bain-Tsagan on the western bank (3–5 July) Zhukov threw a tank brigade straight from the march into battle without infantry cover and forced the Japanese to retreat across the river. From then on it was a conflict between two armies, no longer a quarrel between border guards.

What came of it

The war on the Khalkhin Gol lasted until September. On 20 August 1939, three days before the Molotov–Ribbentrop Pact, Zhukov’s forces went over to the offensive, encircled the Japanese 23rd Division and destroyed it within ten days. On 15 September in Moscow, Molotov and the Japanese ambassador, Shigenori Tōgō, agreed a ceasefire, which came into force the following day. A day later, on 17 September 1939, the Red Army entered Poland: Stalin struck in the west only once he had peace in the east. Japanese losses, according to army figures, reached some 18,000–20,000 killed, wounded and sick; Soviet losses, according to Russian archival data, exceeded 25,000.

The significance of the battle reaches far beyond the steppe by the Khalkhin Gol. The defeat, coinciding with the German–Soviet agreement, which the Japanese saw as a betrayal by Berlin, undermined in Tokyo the “strike north” doctrine (hokushin-ron), long favoured by the army. It was not the only reason for Japan’s turn to the south: that was also driven by the protracted war in China, by the defeats of France and the Netherlands in 1940, which opened the way to their Asian colonies, and above all by oil, which Japan lacked and the Dutch East Indies possessed. The experience of Nomonhan nevertheless meant that when Germany attacked the USSR in June 1941, Japan did not join the war, although it prepared for it throughout the summer. In April 1941 it signed a neutrality pact with the USSR, and in December it struck at Pearl Harbor and the European colonies. The Soviet Union gained quiet in the Far East until August 1945. Masanobu Tsuji, one of those chiefly responsible for the escalation on the Khalkhin Gol, became in 1941 one of the most ardent advocates of war with the United States. Zhukov, for his part, brought back from Mongolia the first of his four Gold Stars of a Hero of the Soviet Union and experience that he put to use in the war against Germany.