From May through September 1939, the Soviet Union and Japan waged hard-fought battles on the wind-swept deserts along the border of eastern Mongolia. Antagonism ran deep. The decline of the Chinese empire had whetted the territorial appetites of its neighbors, and the expanding empires of Russia and Japan collided in Korea and Manchuria. Their conflicting ambitions sparked the Russo-Japanese War of 1904, which ended in a stunning victory for Japan in 1905.
In 1918, following the disintegration of the tsarist empire, the Japanese army occupied Russia’s far eastern provinces and parts of Siberia. The consolidation of the Communist regime, however, compelled a reluctant Japan to withdraw from those territories in 1922. Japan resumed its imperial march in 1931 with the occupation of Manchuria and the establishment of the puppet state of Manchukuo. In 1937, the Japanese invaded China, seizing Shanghai and Nanking.
That, along with the Anti-Comintern Pact signed in 1936 between Germany and Japan, alarmed the Soviet Union. A treaty concluded between Josef Stalin and Chiang Kai-shek’s Kuomintang government in 1937 furnished Soviet financial and military aid to the Chinese. About 450 Soviet pilots and technicians and 225 Soviet warplanes were soon sent to China.
Incidents along the 3,000 miles of ill-defined border between Manchukuo and the Soviet Union numbered in the hundreds from 1932 on. In the summer of 1938, a major clash erupted at Lake Khasan, 70 miles southwest of Vladivostok at the intersection of the Manchukuoan, Korean and Soviet borders, leaving the Soviets in possession of the ground.
The lifeline of the Soviet position in the Far East and Siberia was the Trans-Siberian Railroad, which served as the only link between those regions and European Russia. Outer Mongolia was the key to strategic control of the Trans-Siberian Railroad. To ensure the protection of that vital artery, the Soviets had established the puppet Mongolian People’s Republic (MPR) in Outer Mongolia. A treaty of mutual assistance between the Soviet Union and the MPR had been signed in 1936.
Part of the reason for the escalating tensions in the area was due to the ‘Strike North’ faction in the Japanese high command — a faction found predominantly among the staff officers of the Kwantung Army stationed in Manchukuo. Once it had severed the Trans-Siberian lifeline, the Strike North officers argued, the Japanese empire could then be expanded to include all of Mongolia, the Soviet maritime provinces and parts of Siberia. Shielded by those buffer territories, the natural resources and heavy industries of Manchukuo could then be fully developed by the Japanese. Bereft of outside support, Chinese resistance would collapse.
A minor border dispute in a remote area provided the Strike North faction with the opportunity needed to pursue its ambitious plan. The Japanese claimed the Halha River as the western border of Manchukuo. However, the Soviets argued that the frontier was 15 miles east of the Halha, close to the village of Nomonhan.
The Kwantung Army’s staff was convinced that they enjoyed a decisive logistical advantage in that remote area. Japanese railheads were located 100 miles east of Nomonhan. Two dirt roads had been cleared to the village. In sharp contrast, the nearest Russian railhead was 434 miles away at Borzya. The Japanese were sure that the Russians could not commit more than two infantry divisions to operations in that area. The Japanese were also convinced that Stalin’s Great Purge of 1935 to 1937 had effectively crippled the Soviet officer corps.
The Halha River, often referred to as the Khalkhin Gol, flowed north–south, parallel with the battle front. At the center of the front, the Holsten River bisected the Halha. Terrain was hilly east of the Halha, but west of the river stretched a vast and barren desert plateau. During July and August, temperatures ranged as high as 104 degrees. Available water in the area was brackish, and water purification was a major problem for both armies. Hordes of voracious mosquitoes from the marshes tormented the soldiers of both sides.
In May 1939, a series of Kwantung Army–instigated skirmishes between Mongolian and Manchukuoan forces escalated into what the Soviets would term the Khalkhin Gol and the Japanese would call the Nomonhan Incident. Elements of the Japanese 23rd Division were committed to action on May 14, as were Japanese warplanes. The first major encounter between Japanese and Soviet forces took place between May 28 and 29. Both sides fought to a draw. Having committed themselves, the Japanese were then reinforced and organized under the command of Lt. Gen. Michitaro Komatsubara into an army of 20,000 men and 112 field artillery pieces.
Earlier, in an interview with American journalist Roy Howard on March 1, 1936, Stalin had warned the Japanese that any attack on the MPR would elicit prompt Soviet aid to its client state. That warning was renewed in a speech Stalin made to the 18th Communist Party Congress on March 10, 1939.
On June 2, General Georgi Zhukov, one of the few general officers to survive Stalin’s purges, was entrusted with the command of Soviet and Mongolian troops at Khalkhin Gol. Reflecting the conflict’s importance to the Soviet premier, Zhukov was instructed to report directly to Stalin. Upon his arrival, Zhukov thoroughly organized his command facilities and communications networks. Another hallmark of his leadership, discipline, was ruthlessly enforced among the men of his remote army.
As befitted a battlefield with little or no ground cover, much of the early fighting between Zhukov and Komatsubara’s forces was focused on securing the air. Initially, the Japanese enjoyed an advantage in these encounters. Japanese pilots were experienced veterans of the air war over China. In the spring of 1939, the new Nakajima Ki.27 monoplane fighter — fast and highly maneuverable — entered service with the Japanese army air force. (The formidable Mitsubishi A6M1 Zero did not come into service until September 1940 with the Japanese navy.) Ninety Nakajima fighters and pilots were deployed to contest the skies over Mongolia.
The Japanese pilots soon made their presence felt. Four Soviet aircraft were shot down for every single loss inflicted on their foe. To reverse that situation, in June the Soviets committed six squadrons of improved model Polikarpov I-152 biplanes and three squadrons of Polikarpov I-16 Type 10 monoplanes, totaling more than 100 fighters. The stubby I-152 proved well-suited to operate from hot and windy desert airstrips. It featured a short takeoff run and was very stable, even in crosswinds. The world’s first production monoplane fighter with retractable landing gear, the I-16 was very demanding to fly and unforgiving to inexperienced pilots. The high landing speed of the I-16 required long airstrips. But the ‘flying barrel,’ as the I-16 was dubbed, was fast, climbed rapidly and possessed an outstanding rate of roll.
Although the I-16 could not match the Ki.27’s maneuverability, it could easily dive onto the tail of its adversary and then climb away. Both Soviet fighters packed double the firepower of their antagonist, being armed with four 7.62mm machine guns versus two 7.7mm guns in the Nakajima. Soviet pilots also enjoyed the protection of armor plate incorporated into the seat of the I-152 and the headrest of the I-16 — a feature that the Japanese, in their obsession with saving weight, had left out of their nimble fighters. Operating in close cooperation, the two Russian fighters proved a match for their Japanese challenger.
Among the Soviet fliers dispatched to Mongolia were veterans of the Spanish Civil War. With experienced leadership and new fighters, the Russians turned the air war to their advantage as the summer wore on. Japanese statistics on casualties suffered by their army air force reveal that of those airmen lost in battle, 10.1 percent were killed and wounded in May and June, 26.5 percent in July, 50 percent in August and the rest in the first half of September. Japanese aces rang up fantastic scores during that period — including 58, a Japanese army record, by Hiromichi Shinohara before he was killed in action on August 27. More recent analysis by Japanese aviation historians, however, revealed that while Soviet pilots claimed four times as many victories as they really achieved, their own pilots had over-claimed by a factor of 6-to-1.
Even as its pilots were scoring victories, a growing rift between the Kwantung Army and the army general staff in Tokyo was intensified by the air war. Without prior knowledge or approval of the high command in Tokyo, the Kwantung Army unleashed major bombing raids on June 27 against Tamsag and Bain Tumen air bases, deep in the Soviet rear. Infuriated by such rank insubordination, the officers in Tokyo delivered a blistering rebuke. Orders were issued forbidding attacks upon airfields in Soviet rear areas. The incident illuminated the deep division within Japanese army leadership at the highest levels. Deeply concerned about commitment of Japanese forces in China, the army general staff in Tokyo was beginning to view the escalating conflict in Mongolia with growing alarm.
While Japanese leaders squabbled over their commitment of forces in Mongolia, Zhukov and others began to focus on overcoming the daunting logistical challenges of maintaining a sizable defensive force in the region. In an impressive effort that would provide valuable lessons for future operations, Russian truck convoys drove day and night over desert tracks, a grueling round trip of 868 miles. The Soviets employed 3,800 trucks and 1,375 fuel tankers in their supply organization. Those trucks transported 18,000 tons of artillery shells, 6,500 tons of bombs and 15,000 tons of liquid fuel, as well as troops and weapons. Much of the credit for that remarkable feat of logistics must go to a veteran Soviet general, Grigori M. Shtern, commander of the Trans-Baikal military district.
Unwilling to back down, the Japanese unleashed a major two-pronged ground offensive at the beginning of July. On the left, an attack spearheaded by a mechanized brigade would drive the Soviets back to the Halha. Meanwhile, an attack on the right would cross the river to the north and then sweep south, cutting off the subsequent Soviet retreat.
The mechanized brigade stationed with the Japanese army in Manchukuo was in the process of organization. Only one of three planned medium tank regiments had been fully formed. Production of new Type 97 medium tanks was just underway. The brigade had not yet incorporated integral infantry and artillery components. Three infantry battalions were now hastily withdrawn from other formations and assigned to the brigade for the forthcoming operation.
Only four of the new Type 97 tanks had come into the hands of the 3rd Medium Tank Regiment. That unit was therefore compelled to rely upon 26 of the older Type 89B machines. Weighing 13 tons, the Type 89B was powered by a 120-hp engine and could only make 15.5 mph. Main armament was a low-velocity 57mm gun with limited range and penetration capability. The 4th Light Tank Regiment comprised 35 Type 95 light tanks and eight Type 89A mediums. The Type 95 attained a speed of nearly 28 mph, but its 37mm gun had an effective range of only 700 meters.
In comparison, the main Soviet tank, the 13.8-ton BT-7, featured a powerful 450-hp engine and Christie suspension, giving the machine a speed of 33 mph. Its main armament was an excellent 45mm high-velocity gun, with a range of 2,000 meters. Tanks on both sides were highly vulnerable to anti-tank guns, of which the Soviets possessed an overwhelming majority. A Soviet tank brigade at full strength possessed 128 tanks and 24 self-propelled 76mm howitzers. An armored brigade in the Red Army was a team of tanks, truck mounted infantry and self-propelled artillery. The self-propelled 76mm cannons were mounted on turntables in heavy trucks, and protected with armored shields.
On July 2, 7 1/2 Japanese infantry battalions crossed the Halha and seized the Bain Tsagan Heights. They quickly encountered the 11th Soviet Tank Brigade, which, along with the 7th Armored Brigade, was hurled by Zhukov into a quickly organized counterattack. Possessing few anti-tank guns, the Japanese were compelled to rely on Molotov cocktails and other inadequate explosive charges flung against the Soviet armor. After fierce fighting the Japanese were dislodged from the ridge and forced to withdraw across the Halha. In the subsequent Japanese counterattacks, the infantry failed to work effectively with their armor. Forty-four Japanese tanks were destroyed or damaged. The brigade was withdrawn from the theater on July 10.
Undaunted by previous failures, the Japanese tried again between July 23 and 25. After a preliminary barrage, Japanese infantry would infiltrate Russian positions at night. To give the barrage increased punch, the Japanese brought up six long-barreled, 150mm Type 89 guns and, from the Home Islands, 16 105mm Type 92 guns.
But the Japanese found themselves outranged and outweighed by long-barreled Soviet artillery. The 12 Soviet 150mm guns hit targets accurately at a range beyond the ability of the Japanese to reply. The 16 122mm Soviet model 1931 guns reached up to 20,870 meters, while the Japanese 105mm guns fell short at 18,300 meters. In the ensuing duel, the Japanese failed to silence the heavy Russian artillery.
With their artillery’s lack of effectiveness, the subsequent night attacks by the Japanese infantry units were stopped by formidable Russian defenses. In addition to working to improve his logistical position, Zhukov had worked diligently to prepare an organized defense in depth. Even when Japanese units were able to seize positions, when morning came, Soviet artillery, tanks and infantry recaptured the lost ground.
By the end of July, the Japanese were compelled, with great reluctance, to go on the defensive. Their energies were then devoted to building a system of field fortifications and bunkers. On August 10, Japanese forces fighting along Khalkhin Gol were organized as the Sixth Army. The army included 38,000 soldiers, 318 guns, 130 tanks and 225 warplanes. While the Japanese entrenched themselves, General Zhukov, now commanding the First Army Group, planned to launch an offensive of his own. He would use the 57,000 men, 542 artillery pieces, 498 tanks and 515 aircraft of his army group in a double envelopment of the Japanese.
Even while fending off Japanese attacks earlier in the summer, the Soviet commander had studied his opponents’ dispositions, discovering several fatal flaws. The Japanese flanks were covered by unreliable Manchukuoan cavalry and were vulnerable to encirclement. Nor did the Japanese possess a tactical mobile reserve. To cope with flank attacks, they would be compelled to focus on one flank at a time, and disengage forces from action in the center or the other flank. To secure operational surprise, Zhukov employed many varied deceptive measures. Radios broadcast false information and transmitted soundtracks of construction noise. Trucks and aircraft operated day and night to muffle the sound of unit deployment. Such measures convinced the Japanese that the Soviets were also digging in for the winter.
Poised to strike on August 20 were three major Soviet forces arrayed along a 45-mile front. On the Soviet left wing, facing east, were the 6th Mongolian Cavalry Division, the 7th Armored Brigade, the 601st Infantry Regiment of the 82nd Rifle Division and two battalions of the 11th Tank Brigade. In the center, entrusted with pinning the Japanese in place by a frontal assault, were the 36th Motorized Rifle Division, the 5th Machine Gun Brigade and the 82nd Rifle Division minus the 601st Infantry Regiment. On the right wing, facing north, were the 57th Rifle Division, two battalions of the 11th Tank Brigade, three battalions of the 6th Brigade and the 8th Mongolian Cavalry Division. Held in reserve was a powerful mobile force made up of the 9th Armored Brigade, one battalion of the 6th Tank Brigade and the 212th Airborne Brigade.
At 5:45 on the morning of August 20, Russian aircraft unleashed a hail of bombs on Japanese positions. A heavy barrage thundered from Soviet guns. At 9 a.m., Russian troops moved forward. The climactic battle of Khalkhin Gol was underway. The Japanese were stunned by the ferocity of Zhukov’s attack. The southern Russian force, with the shortest distance to go to reach the Japanese rear, and buttressed with the largest tank strength, made the most progress in the initial onslaught. The central force, however, became entangled in furious fighting. In the north, Soviet troops encountered stubborn and skillful resistance.
Komatsubara was keenly aware of the Soviet threat to his southern flank. He wanted to shift elements of his 23rd Division south to meet it, but Soviet pressure on his beleaguered soldiers in the north compelled the Japanese commander to reinforce that endangered flank instead. Met by Japanese resistance in the north, Zhukov committed the 9th Armored Brigade and the paratroopers of the 212th Brigade to his northern force. As a result, Japanese attention remained focused on the northern flank.
By August 23, the southern Soviet force had driven to the Manchukuoan border and cut off any Japanese retreat from the area below the Holsten River. The encirclement was completed on August 24, when the 9th Armored Brigade linked up with the 8th Armored Brigade from the south.
Japanese forces drawn from Manchukuo made efforts to rescue their trapped comrades from August 24 to 26. Soviet air attacks made any road movement very difficult, however, and a hammer blow by the 6th Tank Brigade finally forced the Japanese to abandon their efforts to break the iron grip of the Soviet vise. Divided into pockets, the Japanese were crushed by August 31.
In the midst of the fighting, the Japanese were shocked and infuriated to learn that their German ally had negotiated and signed a nonaggression pact with the Soviet Union on August 23. Japanese feelings were bitterly summarized by the newspaper Asahi Shimbun: ‘The spirit of the Anti-Comintern Pact has been reduced to a scrap of paper and Germany has betrayed an ally.’ In light of that development and their failure to secure victory on the ground, the Japanese government and army high command in Tokyo concluded that the conflict in Mongolia must be brought to a close.
In September, to discourage any Soviet move into Manchukuo and to prepare for renewed ground action if needed, the Japanese mounted an intense air campaign. For that purpose, six fighter squadrons were transferred from China. By September 13, the Japanese army air force had arrayed 255 warplanes, including 158 fighters along the front. Air battles swirled in Mongolian skies in the first and second weeks of September and climaxed on the 15th, as 200 Japanese warplanes struck Soviet air bases in Mongolia. Fierce aerial combat ensued as 120 Japanese fighters fought 207 Russian adversaries. All combat came to an end, however, when a cease-fire agreement was signed on September 16.
The Japanese conceded the loss of 8,717 soldiers and airmen killed and missing, and 10,997 wounded and ill during their incursion into Mongolia. Soviet sources report 8,931 killed and missing, and 15,952 wounded and sick. But both sides’ losses may well have exceeded those figures.
The scope and results of this conflict were not widely known at the time. Mortified by defeat in battle, the Japanese sought to conceal their disgrace. For its part, the Soviet Union was preoccupied with seizing defensive positions in the West with the division of Poland and the occupation of the Baltic States, and did little to trumpet its victories.
In addition, having killed most of his military leaders in his purges, Stalin was unwilling to promote Zhukov’s victory and see the general emerge as a popular hero. Even so, later actions during the war would ensure that Zhukov would become justly famous as the leading Soviet commander of World War II. Many of the characteristic features of the Russian way of war can be seen in his leadership at Khalkhin Gol: massive firepower; tight integration of infantry, artillery, tanks and warplanes; elaborate deception measures; and ruthless sacrifice of lives.
When Adolf Hitler invaded the Soviet Union in the summer of 1941, the Japanese were tempted to join the assault, but the shadow of Khalkhin Gol haunted them. With the influence of the Strike North group at an end, Japanese military planners began to look at British, French and Dutch colonial possessions in Southeast Asia as offering greater prospects for expansion.
Stalin remembered the fierce fighting in Mongolia as well. Even as he summoned 1,000 tanks and 1,200 warplanes from Soviet Far Eastern forces to battle the German invaders who were making spectacular gains, 19 reserve divisions, 1,200 tanks and some 1,000 aircraft remained in Mongolia to confront the Japanese. Although small by the standards of later World War II battles, the fighting between Soviet and Japanese forces at Khalkhin Gol cast a long shadow over subsequent events in the Pacific theater and on the Russian Front.