Battles of Khalkhin Gol

Mongolian cavalry in the Khalkhin Gol (1939)

Mongolian troops fight against a Japanese counterattack on the western beach of the river Khalkhin Gol, 1939

Japanese soldiers cross the Khalkhin Gol

The incident began on 11 May 1939. A Mongolian cavalry unit of some 70 to 90 men had entered the disputed area in search of grazing for their horses. On that day, Manchu cavalry attacked the Mongolians and drove them back across the river Khalkhin Gol. On 13 May, the Mongolian force returned in greater numbers and the Manchukoans failed to dislodge them.

On 14 May, Lt. Col. Yaozo Azuma led the reconnaissance regiment of the 23rd Infantry Division, supported by the 64th Infantry Regiment of the same division, under Colonel Takemitsu Yamagata, into the territory and the Mongolians withdrew. Soviet and Mongolian troops returned to the disputed region, however, and Azuma's force again moved to evict them, but the Soviet-Mongolian forces surrounded Azuma's force on 28 May and destroyed it.[28] The Azuma force suffered eight officers and 97 men killed and one officer and 33 men wounded, for 63% total casualties.

The commander of the Soviet forces and of the Far East Front was Komandarm Grigori Shtern from May 1938.[29]

Both sides increased their forces in the area. Soon Japan had 30,000 men in the theater. The Soviets dispatched a new corps commander, Comcor Georgy Zhukov, who arrived on 5 June and brought more motorized and armored forces (I Army Group) to the combat zone.[30] Accompanying Zhukov was Comcor Yakov Smushkevich with his aviation unit. J. Lkhagvasuren, Corps Commissar of the Mongolian People's Revolutionary Army, was appointed Zhukov's deputy.

On 27 June the Japanese Army Air Force's 2nd Air Brigade struck the Soviet airbase at Tamsak-Bulak in Mongolia. The Japanese won this engagement, but the strike had been ordered by the Kwantung Army without obtaining permission from Imperial Japanese Army (IJA) headquarters in Tokyo. In an effort to prevent the incident from escalating,[31] Tokyo promptly ordered the JAAF not to conduct any more air-strikes against Soviet airbases.[32]

Destroyed Soviet BA-10 armored car

A destroyed Soviet biplane fighter (presumably an I-15 or an I-153)

Japanese soldiers cheering alongside captured Soviet AFVs

Japanese soldiers posing for a photo with captured Soviet equipment

Crew of a BT-5 cavalry tank surrendering to the Japanese

Throughout June there were reports of Soviet and Mongolian activity on both sides of the river near Nomonhan and small-scale attacks on isolated Manchukoan units. At the end of the month, the commander of the 23rd Japanese Infantry Division, Lt. Gen. Michitarō Komatsubara, received permission to "expel the invaders".

The Japanese planned a two-pronged assault. The first attack would be made by three regiments plus part of a fourth: the 71st and the 72nd Infantry Regiment (23rd Division), a battalion of the 64th Infantry Regiment and the 26th Infantry Regiment under Colonel Shinichiro Sumi (7th Infantry Division). This force would advance across the Khalkin Gol, destroy Soviet forces on Baintsagan Hill on the west bank, then make a left turn and advance south to the Kawatama Bridge. The second prong of the attack would be the task of the IJA 1st Tank Corps (1st TC) (Yasuoka Detachment), consisting of the 3rd and 4th Tank Regiments, plus a part of the 64th Infantry Regiment, a battalion from the 28th Infantry Regiment, detached from the 7th Infantry, 24th Engineer Regiment, and a battalion from the 13th Field-Artillery Regiment, all under the overall command of Lieutenant General Yasuoka Masaomi.[33] This force would attack Soviet troops on the east bank of the Khalkhin Gol and north of the Holsten River. The two Japanese thrusts were to join on the wings.

• Lt. Gen. Yasuoka Masaomi, IJA, Commanding Officer, 1st Tank Corps[33]
  • 3rd Tank Regiment[34]
    • Type 89 I-Go medium tanks – 26
    • Type 97 Chi-Ha medium tanks – 4
    • Type 94 tankettes – 7
    • Type 97 Te-Ke tankettes – 4
  • 4th Tank Regiment[35]
    • Type 95 Ha-Go light tanks – 35
    • Type 89 I-Go medium tanks – 8
    • Type 94 tankettes – 3

The commander of the 149th Rifle Regiment before the offensive

The northern task force succeeded in crossing the Khalkhin Gol, driving the Soviets from Baintsagan Hill, and advancing south along the west bank. However, Zhukov, perceiving the threat, launched a counterattack with 450 tanks and armored cars. The tanks consisted of primarily BTs with a handful of T-26s, while the armored cars were BA-10s and BA-3/6s, which were similar in armor (6–15 mm (0.24–0.59 in)) and armament (main: 45 mm (2 in) gun 20K mod, secondary: two 7.62 mm (0.30 in) machine guns) to the Soviet light tanks. The Soviet armored force, despite being unsupported by infantry, attacked the Japanese on three sides and nearly encircled them. The Japanese force, further handicapped by having only one pontoon bridge across the river for supplies, was forced to withdraw, recrossing the river on 5 July. Meanwhile, the 1st Tank Corps of the Yasuoka Detachment (the southern task force) attacked on the night of 2 July, moving in the darkness to avoid the Soviet artillery on the high ground of the river's west bank. A pitched battle ensued in which the Yasuoka Detachment lost over half its armor, but still could not break through the Soviet forces on the east bank and reach the Kawatama Bridge.[36] After a Soviet counterattack on 9 July threw the battered, depleted Yasuoka Detachment back, it was dissolved and Yasuoka was relieved.[37]

Japanese pilots pictured on a Toyota KC starter truck

The two armies continued to spar with each other over the next two weeks along a four-kilometre (2.5 mi) front running along the east bank of the Khalkhin Gol to its junction with the Holsten River.[38] Zhukov, whose army was 748 km (465 mi) away from its base of supply, assembled a fleet of 2,600 trucks to supply his troops, while the Japanese suffered severe supply problems due to a lack of similar motor transport.[32] On 23 July, the Japanese launched another large-scale assault, sending the 64th and 72nd Infantry Regiments against Soviet forces defending the Kawatama Bridge. Japanese artillery supported the attack with a massive barrage that consumed more than half of their ammunition stores over a period of two days.[39] The attack made some progress but failed to break through Soviet lines and reach the bridge. The Japanese disengaged from the attack on 25 July due to mounting casualties and depleted artillery stores. By this point they had suffered over 5,000 casualties between late May and 25 July, with Soviet losses being much higher but more easily replaced.[32][40] The battle drifted into a stalemate.

BT-7 Tanks in the Battle of Khalkhin Gol

With war apparently imminent in Europe, and to avoid fighting a two front war, Zhukov planned a major offensive on 20 August 1939 to clear the Japanese from the Khalkhin Gol region and to end the fighting.[41] Zhukov, using a fleet of at least 4,000 trucks (IJA officers with hindsight disputed this, saying he instead used 10,000 to 20,000 motor vehicles) transporting supplies from the nearest base in Chita (600 km (370 mi) away)[7] assembled a powerful armored force of three tank brigades (the 4th, 6th and 11th), and two mechanized brigades (the 7th and 8th, which were armored car units with attached infantry support). This force was allocated to the Soviet left and right wings. The entire Soviet force consisted of three rifle divisions, two tank divisions and two more tank brigades (in all, some 498 BT-5 and BT-7 tanks),[42] two motorized infantry divisions, and over 550 fighters and bombers.[43] The Mongolians committed two cavalry divisions.[44][45][46]

In comparison, at the point of contact, the Kwantung Army had only the 23rd Infantry Division, which with various attached forces was equivalent to two light infantry divisions. Its headquarters had been at Hailar, over 150 km (93 mi) from the fighting. Japanese intelligence, despite demonstrating an ability to track the build-up of Zhukov's force, failed to precipitate an appropriate response from below.[47] Thus, when the Soviets finally did launch their offensive, Komatsubara was caught off-guard.[47][48] To test the Japanese defences prior to their main assault on 20 August, the Soviets launched three aggressive probing assaults, one on 3 August and the others on 7/8 August. All three were disastrously thrown back, with around 1,000 combined dead and several tanks knocked out on the Soviet side compared to just 85 Japanese casualties.[49] The Japanese counterattacked and routed elements of the Mongolian 8th Cavalry Division, seizing a hilly sector of the battlefront.[50] Despite the fact that no more major fighting would take place until 20 August, Japanese casualties continued to mount at a rate of 40 wounded per day.[51] Kwantung Army staff officers were becoming increasingly worried over the disorganized state of the 6th Army headquarters and supply elements. The growing casualty count meant that the green 23rd Division would have to take, train and assimilate new replacements "on the job".[51] By contrast, Tokyo's oft-stated desire that it would not escalate the fighting at Khalkhin Gol proved immensely relieving to the Soviets, freed to hand-pick select units from across the military to be concentrated for a local offensive without fear of Japanese retaliation elsewhere.[52]

Zhukov decided it was time to break the stalemate.[43] At 05:45 on 20 August 1939, Soviet artillery and 557 aircraft[43] attacked Japanese positions, the first fighter-bomber offensive in Soviet Air Force history.[53] Approximately 50,000 Soviet and Mongolian soldiers of the 57th Special Corps attacked the east bank of the Khalkhin Gol. Three infantry divisions and a tank brigade crossed the river, supported by massed artillery and by the Soviet Air Force. Once the Japanese were pinned down by the attack of Soviet center units, Soviet armored units swept around the flanks and attacked the Japanese in the rear, achieving a classic double envelopment. When the Soviet wings linked up at Nomonhan village on 25 August, they trapped the Japanese 23rd Infantry Division.[32][54][55] On 26 August, a Japanese counterattack to relieve the 23rd Division failed. On 27 August the 23rd Division attempted to break out of the encirclement but failed. When the surrounded forces refused to surrender, they were again hit with artillery and air attacks. By 31 August, Japanese forces on the Mongolian side of the border were destroyed, leaving remnants of the 23rd Division on the Manchurian side. The Soviets had achieved their objective.[56]

Captured Japanese soldiers

Captured Japanese Type 95 scout car

The Soviet Union and Japan agreed to a cease-fire on 15 September; it took effect the following day at 1:10 pm.[32][57][58]

Combat losses include aircraft shot down during aerial combat, written off due to combat damage or destroyed on the ground.

Non-combat losses include aircraft that were lost due to accidents, as well as write-offs of warplanes due to the end of their service life. Thus Soviet combat losses amount to 163 fighters, 44 bombers, and a reconnaissance aircraft, with further 385 fighters and 51 bombers requiring repairs due to combat damage. VVS (Soviet Air Forces) personnel losses were 88 killed in aerial combat, 11 killed by anti-aircraft artillery, 65 missing, six killed in air-strikes and four died of wounds (174 total) and 113 wounded. The Japanese combat losses were 97 fighters, 25 bombers and 41 other (mostly reconnaissance), while 128 fighters, 54 bombers and 38 other required repairs due to combat damage. The Japanese Air Force suffered 152 dead and 66 severely wounded.

USSR: Bomber sorties 2,015, fighter sorties 18,509; 7.62 mm machine gun rounds fired 1,065,323; 20 mm (0.80 in) cannon rounds expended 57,979; bombs dropped 78,360 (1,200 tons).

Japan: Fighter/bomber sorties 10,000 (estimated); 7.7 mm (0.30 in) machine gun rounds fired 1.6 million; bombs dropped 970 tons.[66]

The battle was the first victory for the soon-to-be-famous Soviet general Georgy Zhukov, earning him the first of his four Hero of the Soviet Union awards. The two other generals, Grigori Shtern and Yakov Smushkevich, had important roles and were also awarded the Hero of the Soviet Union. They would, however, both be executed in the 1941 Purges. Zhukov himself was promoted and transferred west to the Kiev district. The battle experience gained by Zhukov was put to good use in December 1941 at the Battle of Moscow. Zhukov was able to use this experience to launch the first successful Soviet counteroffensive against the German invasion of 1941. Many units of the Siberian and other trans-Ural armies were part of this attack, and the decision to move these divisions from Siberia was aided by the Soviet spy Richard Sorge in Tokyo, who alerted the Soviet government that the Japanese were looking south and were unlikely to launch another attack against Siberia in the immediate future. A year after defending Moscow against the advancing Germans, Zhukov planned and executed the Red Army's offensive at the Battle of Stalingrad, using a technique very similar to Khalkhin Gol, in which the Soviet forces held the enemy fixed in the center, built up an undetected mass force in the immediate rear area, and launched a pincer attack on the wings to trap the German army.

Following the battle, the Soviets generally found the results unsatisfactory, despite their victory. Though the Soviet forces in the Far East in 1939 were not plagued by fundamental issues to the same extent as those in Europe during the 1941 campaigns, their generals were still unimpressed by their army's performance. As noted by Pyotr Grigorenko, the Red Army went in with a very large advantage in technology, numbers and firepower, yet still suffered huge losses, which he blamed on poor leadership.[29]

Although their victory and the subsequent negotiation of the Soviet–Japanese Neutrality Pact secured the Far East for the duration of the Soviet-German War, the Red Army always remained cautious about the possibility of another, larger Japanese incursion as late as early 1944. In December 1943, when the American military mission proposed a logistics base be set up east of Lake Baikal, the Red Army authorities were according to Coox "shocked by the idea and literally turned white".[73] Due to this caution, the Red Army kept a large force in the Far East even during the bleakest days of the war in Europe. For example, on July 1, 1942, Soviet forces in the Far East consisted of 1,446,012 troops, 11,759 artillery pieces, 2,589 tanks and self-propelled guns, and 3,178 combat aircraft.[74] Despite this, the Soviet operations chief of the Far Eastern Front, General A. K. Kazakovtsev, was not confident in his army group's ability to stop an invasion if the Japanese committed to it (at least in 1941–1942), commenting: "If the Japanese enter the war on Hitler's side ... our cause is hopeless."[75]

The Japanese similarly considered the result not a failing of tactics, but one that simply highlighted a need to address the material disparity between themselves and their neighbours.[76][77] They made several reforms as a result of this battle: Tank production was increased from 500 annually to 1,200 in 1939. A mechanized headquarters was established in early 1941, and the new Type 1 47 mm anti-tank gun was introduced as a response to the Soviet 45 mm. These cannons were mounted on Type 97 Chi-Ha tanks, resulting in the Type 97 ShinHoTo Chi-Ha ("New Turret") variant, which became the IJA's standard medium tank by 1942. IGHQ also dispatched General Tomoyuki Yamashita to Germany in order to learn more about tank tactics, following the crushingly one-sided Battle of France and the signing of the Tripartite Pact. He returned with a report where he stressed the need for mechanization and more medium tanks. Accordingly, plans were put underway for the formation of 10 new armoured divisions in the near future.[12]

Despite all of the above, Japanese industry was not productive enough to keep up with either the United States or the Soviet Union, and Yamashita warned against going to war with them for this reason. His recommendations were not taken to heart, and Japanese militarists eventually successfully pushed for war with the United States. In spite of their recent experience and military improvements, the Japanese would generally continue to underestimate their adversaries, emphasizing the courage and determination of the individual soldier as a way to make up for their lack of numbers and smaller industrial base. To varying degrees, the basic problems that faced them at Khalkhin Gol would haunt them again when the Americans and British recovered from their defeats of late 1941 and early 1942 and turned to the conquest of the Japanese Empire.[32][78]

Also, events exposed a severe lack of procedures for emergency staunching of bleeding. The original Japanese doctrine explicitly forbade first aid to fellow soldiers without prior orders from an officer, and first-aid training was lacking. As result, a large proportion of Japanese dead was due to hemorrhaging from untreated wounds. Furthermore, up to 30% of the total casualties were due to dysentery, which the Japanese believed was delivered by Soviet biological-warfare aerial bombs. To reduce susceptibility to diseases, future Japanese divisions would commonly include specialized Epidemic Prevention and Water Purification Departments.[79] Finally, the Japanese food rations were found to be unsatisfactory, both in packing and in nutritional value.[80]

The anniversary of the battle was first celebrated in 1969, on the occasion of its 30th anniversary. After its 50th anniversary, in 1989, it dwindled in importance, going down to the level of academic debates and lectures. Only recently has the anniversary made a resurgence as an important event in Mongolian history.[82]

The Mongolian town of Choibalsan, in the Dornod Province where the battle was fought, is the location of the "G. K. Zhukov Museum", dedicated to Zhukov and the 1939 battle.[83] Ulaanbaatar also has a "G. K. Zhukov Museum" with information about the battle.[84] The latter museum was opened on 19 August 1979 in the presence of Yumjaagiin Tsedenbal and Zhukov's three daughters.[85] During the 70th, 75th and 80th anniversaries of the battle in 2009, 2014 and 2019, respectively, the President of Russia has taken part in the celebrations alongside the President of Mongolia and Soviet and Mongolian veterans, with the celebration often coinciding with a state visit.

Troops of the Mongolian Armed Forces during the 80th anniversary parade in 2019

On the 80th anniversary, in 2019, a military parade was held in Choibalsan on Independence Square, which featured tactical formations of the Russian Armed Forces' Eastern Military District and the Mongolian Armed Forces, all of whom were participants in the joint Russian-Mongolian military exercises "Selenga-2019" the previous month.[86][87][88] Parades were held in the federal subjects of Russia that surround and have a close relationship with Mongolia, such as Buryatia, Yakutia and the Altai Republic. In the Buryat capital of Ulan-Ude, a parade was held in the capital.[89][90] In addition, a concert on Sükhbaatar Square took place on 28 August, during which the Russian Alexandrov Ensemble together with the Mongolian singers gave a performance.[91]