Soviet -- Japanese war - wikipedia Soviet -- Japanese war For the war in 1904 -- 05, see Russo - Japanese War. For the border conflicts in the 1930s, see Soviet -- Japanese border conflicts. Soviet - Japanese War Part of the Pacific Theater of World War II US - Soviet sailors on VJ Day Date August 9 -- September 2, 1945 ( 3 weeks and 3 days ) Location Manchuria / Manchukuo, Inner Mongolia / Mengjiang, Sakhalin, the Kuril Islands, and northern Korea Result Allied victory Belligerents Soviet Union Mongolia Japan Japanese Korea Manchukuo Mengjiang Commanders and leaders Aleksandr Vasilevsky Ivan Yumashev Otozō Yamada ( POW ) Units involved Western Front 17th Army 36th Army 39th Army 53rd Army 6th Guards Tank Army Mongolian Cavalry Group 12th Air Army Eastern Front 1st Red Banner Army 5th Army 25th Army 35th Army 10th Mechanized Corps 9th Air Army Northern Front 2nd Red Banner Army 15th Army 16th Army 5th Separate Rifle Corps Chuguevsk Operational Group Amur Military Flotilla 10th Air Army Kwangtung Army First Area Army 3rd Army 5th Army Third Area Army 30th Army 44th Army Independent units 4th Army 34th Army Fifth Area Army Manchukuo Imperial Army Mengjiang National Army Strength Soviet Union : 1,577,225 men, 26,137 artillery, 1,852 sup. artillery, 5,556 tanks and self - propelled artillery 5,368 aircraft Mongolia : 16,000 men Japan : 983,000 men, 5,360 artillery, 1,155 tanks, 1,800 aircraft, 1,215 vehicles Manchukuo : 170,000 men Mengjiang : 44,000 men Casualties and losses 12,031 killed 24,425 wounded Japanese claim : 21,389 killed 20,000 wounded 41,199 captured Soviet claim : 83,737 killed 600,000 captured Campaigns of World War II Europe Poland Phoney War Winter War Denmark & Norway France & Benelux Britain Balkans Eastern Front Finland Western Front ( 1944 -- 45 ) Pacific War China Pacific Ocean South - East Asia South West Pacific Japan Manchuria ( 1945 ) Mediterranean and Middle East North Africa Horn of Africa Mediterranean Sea Adriatic Malta Yugoslavia Iraq Syria -- Lebanon Iran Italy Dodecanese Southern France Other campaigns Atlantic Arctic Strategic bombing America French West Africa Madagascar Contemporaneous wars Chinese Civil War USSR -- Japan Border Wars French -- Thai Ecuadorian -- Peruvian War Ili Rebellion The Soviet -- Japanese War ( Russian : Советско - японская война ; Japanese : ソ連 対日 参戦, `` Soviet Union entry into war against Japan '' ) was a military conflict within the Second World War beginning soon after midnight on August 9, 1945, with the Soviet invasion of the Japanese puppet state of Manchukuo. The Soviets and Mongolians terminated Japanese control of Manchukuo, Mengjiang ( Inner Mongolia ), northern Korea, Karafuto, and the Chishima Islands. The defeat of Japan 's Kwantung Army helped in the Japanese surrender and the termination of World War II. The Soviet entry into the war was a significant factor in the Japanese government 's decision to surrender unconditionally, as it made apparent the Soviet Union would no longer be willing to act as a third party in negotiating an end to hostilities on conditional terms. Contents 1 Summary 2 Background and buildup 3 Combatant forces 3.1 Soviets 3.2 Japanese 4 Campaign 5 Importance and consequences 6 See also 7 Notes 8 References 9 Further reading 9.1 Japanese Monographs 10 External links Summary At the Tehran Conference in November 1943, Stalin agreed that the Soviet Union would enter the war against Japan once Nazi Germany was defeated. At the Yalta Conference in February 1945, Stalin agreed to Allied pleas to enter World War II 's Pacific Theater within three months of the end of the war in Europe. On July 26, the US, UK and China made the Potsdam Declaration, an ultimatum calling for the Japanese surrender which if ignored would lead to their `` prompt and utter destruction ''. The commencement of the invasion fell between the American atomic bombings of Hiroshima on August 6 and Nagasaki on August 9. Although Soviet leader Joseph Stalin had not been told much detail of the Western Allies ' atomic bomb program by Allied governments, by virtue of the timing of the agreements at Tehran and Yalta, and the long term buildup of Soviet forces in the Far East since Tehran, it is clear that news of the attacks on the two cities played no major role in the timing of the Soviet invasion ; the date of the invasion was foreshadowed by the Yalta agreement, the date of the German surrender, and the fact that on August 3, Marshal Vasilevsky reported to Stalin that, if necessary, he could attack on the morning of August 5. Furthermore, while Stalin could reasonably have concluded that an atomic bombing of Japan was imminent, it does not appear he was overly impressed with the atomic bomb 's potential, certainly not so much so as to think it might compel into capitulation a nation as averse to surrender as Japan. At 11pm Trans - Baikal time on August 8, 1945, Soviet foreign minister Molotov informed Japanese ambassador Satō that the Soviet Union had declared war on the Empire of Japan, and that from August 9 the Soviet Government would consider itself to be at war with Japan. At one minute past midnight Trans - Baikal time on August 9, 1945, the Soviets commenced their invasion simultaneously on three fronts to the east, west and north of Manchuria. The operation was subdivided into smaller operational and tactical parts : Khingan - Mukden Offensive Operation ( August 9, 1945 -- September 2, 1945 ) Harbin - Kirin Offensive Operation ( August 9, 1945 -- September 2, 1945 ) Sungari Offensive Operation ( August 9, 1945 -- September 2, 1945 ) and subsequently South Sakhalin Operation ( ru ) ( August 11, 1945 -- August 25, 1945 ) Soviet assault on Maoka Soviet assault on Tōro ( ru ) Seisin Landing Operation ( August 13, 1945 -- August 16, 1945 ) Kuril Landing Operation ( August 18, 1945 -- September 1, 1945 ) Though the battle extended beyond the borders traditionally known as Manchuria -- that is, the traditional lands of the Manchus -- the coordinated and integrated invasions of Japan 's northern territories has also been called the Battle of Manchuria. Since 1983, the operation has sometimes been called Operation August Storm, after American Army historian Lieutenant - Colonel David Glantz used this title for a paper on the subject. It has also been referred to by its Soviet name, the Manchurian Strategic Offensive Operation, however this name refers more to the Soviet invasion of Manchuria ( 1945 ) than to the whole war. This offensive should not be confused with the Soviet -- Japanese Border Wars, ( particularly the Battle of Khalkhin Gol / Nomonhan Incident of May -- September 1939 ), that ended in Japan 's defeat in 1939, and led to the Soviet -- Japanese Neutrality Pact. Background and buildup See also : End of World War II in Asia The Russo - Japanese War of the early 20th century resulted in a Japanese victory and the Treaty of Portsmouth by which, in conjunction with other later events including the Mukden Incident and Japanese invasion of Manchuria in September 1931, Japan eventually gained control of Korea, Manchuria and Southern Sakhalin. In the late 1930s there were a number of Soviet - Japanese border incidents, the most significant being the Battle of Lake Khasan ( Changkufeng Incident, July -- August 1938 ) and the Battle of Khalkhin Gol ( Nomonhan Incident, May -- September 1939 ), which led to the Soviet -- Japanese Neutrality Pact of April 1941. The Neutrality Pact freed up forces from the border incidents and enabled the Soviets to concentrate on their war with Germany, and the Japanese to concentrate on their southern expansion into Asia and the Pacific Ocean. However, with success at Stalingrad, and the eventual defeat of Germany becoming increasingly certain, the Soviet attitude to Japan changed, both publicly, with Stalin making speeches denouncing Japan, and `` privately '', with the Soviets building up forces and supplies in the Far East. At the Tehran Conference ( November 1943 ), amongst other things, Winston Churchill, Franklin Roosevelt and Stalin agreed that the Soviet Union would enter the war against Japan once Nazi Germany was defeated. However, Stalin faced a dilemma -- he wanted to avoid a two - front war at almost any cost yet the Soviet leader also wanted to extract gains in the Far East as well as Europe. The only way Stalin could make Far Eastern gains without a two - front war would be for Germany to capitulate before Japan. Due to the Soviet -- Japanese Neutrality Pact, the Soviets made it policy to intern Allied aircrews who landed in Soviet territory following operations against Japan, although airmen held in the Soviet Union under such circumstances were usually allowed to `` escape '' after some period of time. Nevertheless, even before the defeat of Germany the Soviet buildup in the Far East steadily accelerated. By early 1945 it had become apparent to the Japanese that the Soviets were preparing to invade Manchuria, though they were unlikely to attack prior to Germany 's defeat. In addition to their problems in the Pacific, the Japanese realised they needed to determine when and where a Soviet invasion would occur. At the Yalta Conference ( February 1945 ), amongst other things, Stalin secured from Roosevelt the promise of Stalin 's Far Eastern territorial desires, in return agreeing to enter the Pacific war within two or three months of the defeat of Germany. By the middle of March 1945, things were not going well in the Pacific for the Japanese, and they withdrew their elite troops from Manchuria to support actions in the Pacific. Meanwhile, the Soviets continued their Far Eastern buildup. The Soviets had decided that they did not wish to renew the Neutrality Pact. The terms of the Neutrality Pact required that 12 months before its expiry, the Soviets must advise the Japanese of this, so on 5 April 1945 they informed the Japanese that they did not wish to renew the treaty. This caused the Japanese considerable concern, but the Soviets went to great efforts to assure the Japanese that the treaty would still be in force for another twelve months, and that the Japanese had nothing to worry about. On 9 May 1945 ( Moscow time ), Germany surrendered, meaning that if the Soviets were to honour the Yalta agreement, they would need to enter war with Japan by 9 August 1945. The situation continued to deteriorate for the Japanese, and they were now the only Axis power left in the war. They were keen to remain at peace with the Soviets and extend the Neutrality Pact, and they were also keen to achieve an end to the war. Since Yalta they had repeatedly approached, or tried to approach, the Soviets in order to extend the neutrality pact, and to enlist the Soviets in negotiating peace with the allies. The Soviets did nothing to discourage these Japanese hopes, and drew the process out as long as possible ( whilst continuing to prepare their invasion forces. ) One of the roles of the Cabinet of Admiral Baron Suzuki, which took office in April 1945, was to try to secure any peace terms short of unconditional surrender. In late June they approached the Soviets, ( the Neutrality Pact was still in place ), inviting them to negotiate peace with the allies in support of Japan, providing them with specific proposals and in return they offered the Soviets very attractive territorial concessions. Stalin expressed interest, and the Japanese awaited the Soviet response. The Soviets continued to avoid providing a response. The Potsdam Conference was held from 16 July to 2 August 1945. On 24 July the Soviet Union recalled all embassy staff and families from Japan. On 26 July the conference produced the Potsdam Declaration whereby Churchill, Truman and Chiang Kai - shek ( the Soviet Union was not at war with Japan ) demanded the unconditional surrender of Japan. The Japanese continued to wait for the Soviet response, and avoided responding to the declaration. The Japanese had been monitoring Trans - Siberian Railway traffic and Soviet activity to the east of Manchuria and in conjunction with the Soviet delaying tactics, this suggested to them that the Soviets would not be ready to invade east Manchuria before the end of August. They did not, however, have any real idea, and no confirming evidence, as to when or where any invasion would occur. The Japanese were caught completely by surprise when the Soviets declared war an hour before midnight on 8 August 1945, and invaded simultaneously on three fronts just after midnight on 9 August. Combatant forces See Soviet invasion of Manchuria ( 1945 ) # Combatant forces for the tactical details of the combatant forces and of the invasion. Soviets The Far East Command, under Marshal of the Soviet Union Aleksandr Vasilevsky, had a plan for the conquest of Manchuria that was simple but huge in scale, calling for a massive pincer movement over all of Manchuria. This pincer movement was to be performed by the Transbaikal Front from the west and by the 1st Far East Front from the east ; the 2nd Far East Front was to attack the center of the pocket from the north. The only Soviet equivalent of a theater command that operated during the war ( apart from the short - lived 1941 `` Directions '' in the west ), Far East Command, consisted of three Red Army fronts. Actual map showing the Soviet invasion plan for Manchuria Western Front of Manchuria The Transbaikal Front, under Marshal R.Y. Malinovsky, was to form the western half of the Soviet pincer movement, attacking across the Inner Mongolian desert and over the Greater Khingan mountains. These forces had the objective to secure Mukden ( present day Shenyang ), then meet troops of the 1st Far East Front at the Changchun area in south central Manchuria, and in doing so finish the double envelopment. Eastern Front of Manchuria The 1st Far East Front, under Marshal K.A. Meretskov, was to form the eastern half of the pincer movement. This attack involved striking towards Mudanjiang ( or Mutanchiang ), and once that city was captured, the force was to advance towards the cities of Jilin ( or Kirin ), Changchun and Harbin. Its final objective was to link up with forces of the Trans - Baikal Front at Changchun and Jilin ( or Kirin ) thus closing the double envelopment movement. As a secondary objective, the 1st Far East Front was to prevent Japanese forces from escaping to Korea, and then invade the Korean Peninsula up to the 38th parallel, establishing in the process what later became North Korea. Northern Front of Manchuria The 2nd Far East Front, under General M.A. Purkayev, was in a supporting attack role. Its objectives were the cities of Harbin and Tsitsihar, and the prevention of an orderly withdrawal to the south by the Japanese forces. Once troops from the 1st Far East Front and Trans - Baikal Front captured the city of Changchun, the 2nd Far East Front were to attack the Liaotung Peninsula and seize Port Arthur ( present day Lüshun ). Each Front had `` front units '' attached directly to the Front instead of an army. The forces totaled 89 divisions with 1.5 million men, 3,704 tanks, 1,852 self propelled guns, 85,819 vehicles and 3,721 aircraft. Approximately one - third of its strength was in combat support and services. Its naval forces contained 12 major surface combatants, 78 submarines, numerous amphibious craft, and the Amur River flotilla, consisting of gunboats and numerous small craft. The Soviet plan incorporated all the experience in maneuver warfare that the Soviets had acquired fighting the Germans, and also used new improved weapons, such as the RPD light machine gun, the new main battle tank T - 44 and a little number of JS - 3 heavy tanks. Japanese The Kwantung Army of the Imperial Japanese Army, under General Otozō Yamada, was the major part of the Japanese occupation forces in Manchuria and Korea, and consisted of two Area Armies ( the First Area Army ( northeastern Manchukuo ) and the Third Area Army ( southwestern Manchukuo ) ), and three independent armies ( responsible for northern Manchuria, North Korea, Mengjiang, South Sakhalin and the Kurils ). Each Area Army ( Homen Gun, the equivalent of a Western `` army '' ) had headquarters units and units attached directly to the Area Army, in addition to the field armies ( the equivalent of a Western corps ). In addition to the Japanese, there was the forty - thousand - strong Manchukuo Defense Force, composed of eight under - strength, poorly equipped, poorly trained Manchukuoan divisions. The Kwantung Army had less than eight hundred thousand ( 800,000 ) men in twenty - five divisions ( including two tank divisions ) and six Independent Mixed Brigades. These contained over 1,215 armored vehicles ( mostly armored cars and light tanks ), 6,700 artillery pieces ( mostly light ), and 1,800 aircraft ( mostly trainers and obsolete types ). The Imperial Japanese Navy did not contribute to the defense of Manchuria, the occupation of which it had always opposed on strategic grounds. Additionally, by the time of the invasion, the few remnants of its fleet were stationed and tasked with the defense of the Japanese home island in the event of an invasion by American forces. On economic grounds, Manchuria was worth defending since it had the bulk of usable industry and raw materials outside Japan and was still under Japanese control in 1945. However, the Japanese forces ( Kwantung Army ) were far below authorized strength ; most of their heavy military equipment and all of their best military units had been transferred to the Pacific front over the previous three years to contend with the advance of American and Allied forces. By 1945, the Kwantung Army contained a large number of raw recruits and conscripts, with generally obsolete, light, or otherwise limited equipment. As a result, it had essentially been reduced to a light infantry counter-insurgency force with limited mobility or ability to fight a conventional land war against a coordinated enemy. Compounding the problem, the Japanese military made many wrong assumptions and major mistakes, the two most significant being : They wrongly assumed that any attack coming from the west would follow either the old railroad line to Hailar, or head into Solun from the eastern tip of Mongolia. The Soviets did attack along those routes, but their main attack from the west went through the supposedly impassable Greater Khingan range south of Solun and into the center of Manchuria. Japanese military intelligence failed to determine the nature, location and scale of the Soviet buildup in the Far East. Based on initial underestimates of Soviet strength, and the monitoring of Soviet traffic on the Trans - Siberian railway, they believed the Soviets would not have sufficient forces in place before the end of August, and that an attack was most likely in the autumn of 1945 or in the spring of 1946. Due to the withdrawal of the Kwantung Army 's elite forces for redeployment into the Pacific Theatre, new operational plans for the defence of Manchuria against a seemingly inevitable Soviet attack were made by the Japanese in the summer of 1945. These called for the redeployment of the majority of forces from the border areas ; the borders were to be held lightly and delaying actions fought while the main force was to hold the southeastern corner in strength ( so defending Korea from attack ). Further, they had only observed Soviet activity on the Trans - Siberian railway and along the east Manchurian front, and so were preparing for an invasion from the east. They believed that when an attack occurred from the west, the redeployed forces would be able to deal with it. However, although this redeployment had been initiated, it was not due to be completed until September, and hence the Kwantung Army were in the middle of redeployment when the Soviets launched their attack simultaneously on all three fronts. Campaign This section does not cite any sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. ( August 2009 ) Main article : Soviet invasion of Manchuria The operation was carried out as a classic double pincer movement over an area the size of Western Europe. In the western pincer, the Red Army advanced over the deserts and mountains from Mongolia, far from their resupply railways. This confounded the Japanese military analysis of Soviet logistics, and the defenders were caught by surprise in unfortified positions. The Kwantung Army commanders were involved in a planning exercise at the time of the invasion, and were away from their forces for the first eighteen hours of conflict. Communication infrastructure was poor, and communication was lost with forward units very early on. However, the Kwantung Army had a formidable reputation as fierce and relentless fighters, and even though understrength and unprepared, put up strong resistance at the town of Hailar which tied down some of the Soviet forces. At the same time, Soviet airborne units were used to seize airfields and city centers in advance of the land forces, and to ferry fuel to those units that had outrun their supply lines. The Soviet pincer from the east crossed the Ussuri and advanced around Khanka Lake and attacked towards Suifenhe, and although Japanese defenders fought hard and provided strong resistance, the Soviets proved overwhelming. Perhaps the most glaring fact illustrating the differences in efficacy between the two opponents was that, often, the speed of Soviet advances far outpaced any sort of fighting withdrawal the Japanese could conduct, which formed a crucial element of the entire Japanese strategy for defending the Manchurian heartland. After a week of fighting, during which Soviet forces had penetrated deep into Manchukuo, Japan 's Emperor Hirohito recorded the Gyokuon - hōsō which was broadcast on radio to the Japanese nation on August 15, 1945. The idea of surrender was incomprehensible to the Japanese people, and combined with Hirohito 's use of formal and archaic language, the fact that he did not use the actual word `` surrender '', the poor quality of the broadcast, and poor lines of communication, there was some confusion amongst the Japanese about what the announcement actually meant. The Imperial Japanese Army Headquarters did not immediately communicate the cease - fire order to the Kwantung Army, and many elements of the army either did not understand it, or ignored it. Hence, pockets of fierce resistance from the Kwantung Army continued, and the Soviets continued their advance, largely avoiding the pockets of resistance, reaching Mukden, Changchun and Qiqihar by August 20. On the Soviet right flank, the Soviet - Mongolian Cavalry - Mechanized Group had entered Inner Mongolia and quickly took Dolon Nur and Kalgan. The Emperor of Manchukuo ( and former Emperor of China ), Puyi, was captured by the Soviet Red Army. The cease - fire order was eventually communicated to the Kwantung Army, but not before the Soviets had made most of their territorial gains. On August 18, several Soviet amphibious landings had been conducted ahead of the land advance : three in northern Korea, one in Sakhalin island, and one in the Chishima Islands. This meant that, in Korea at least, there were already Soviet soldiers waiting for the troops coming overland. In Karafuto and the Chishimas, it meant a sudden and undeniable establishment of Soviet sovereignty. On August 10, US government proposed to the Soviet government that they divide the occupation of Korea between them at the 38th parallel north. The Americans were surprised that the Soviet government accepted. Soviet troops were able to move freely by rail, and there was nothing to stop them occupying the whole of Korea. Soviet forces began amphibious landings in Korea by August 14 and rapidly took over the north - east of the country, and on August 16 they landed at Wonsan. On August 24, the Red Army entered Pyongyang and established a military government over Korea north of the parallel. American forces landed at Incheon on September 8 and took control of the south. Importance and consequences Ca. 1,831,000 Soviet personnel have been awarded the Medal `` For the Victory over Japan '' since 30 September 1945. See also : Evacuation of Manchukuo, Occupation of Japan, and Japanese prisoners of war in the Soviet Union From the time of the first major Japanese military defeats in the Pacific in the summer of 1942, the non-military leaders of Japan had come to realise that the Japanese military campaign was economically unsustainable -- as Japan did not have the industrial capacity to simultaneously fight the United States, China and the British Commonwealth and Empire -- and there were a number of initiatives to negotiate a cessation of hostilities and the consolidation of Japanese territorial and economic gains. Hence, elements of the non-military leadership had first made the decision to surrender as early as 1943 ; the major issue was the terms and conditions of surrender, not the issue of surrender itself. For a variety of diverse reasons, none of the initiatives were successful, the two major reasons being the Soviet Union 's deception and delaying tactics, and the attitudes of the `` Big Six '', the powerful Japanese military leaders. ( Refer to Surrender of Japan for more detail. ) The Manchurian Strategic Offensive Operation, along with the atomic bombings of Hiroshima and Nagasaki, combined to break the Japanese political deadlock and force the Japanese leaders to accept the terms of surrender demanded by allies. In the `` Sixty years after Hiroshima '' issue of the Weekly Standard, American historian Richard B. Frank points out that there are a number of schools of thought with varying opinions of what caused the Japanese to surrender. He describes what he calls the `` traditionalist '' view, which asserts that the Japanese surrendered because the Americans dropped the atomic bombs. He goes on to summarise other points of view. Tsuyoshi Hasegawa 's research has led him to conclude that the atomic bombings were not the principal reason for Japan 's capitulation. He argues that Japan 's leaders were impacted more by the swift and devastating Soviet victories on the mainland in the week following Joseph Stalin 's August 8 declaration of war because the Japanese strategy to protect the home islands was designed to fend off a US invasion from the South, and left virtually no spare troops to counter a Soviet threat from the North. Furthermore, the Japanese could no longer hope to achieve a negotiated peace with the Allies by using the Soviet Union as a mediator with the Soviet declaration of war. This, according to Hasegawa, amounted to a `` strategic bankruptcy '' for the Japanese and forced their message of surrender on August 15, 1945. Others with similar views include The `` Battlefield '' series documentary, among others, though all, including Hasegawa, state that the surrender was not due to any single factor or single event. The Soviet invasion and occupation of the defunct `` Manchukuo '' marked the start of a traumatic period for the more - than - one - million occupants of the puppet state who were of Japanese descent. The situation for the Japanese military occupants was clear, but the Japanese colonists who had made `` Manchukuo '' their home, particularly those born in `` Manchukuo '', were now stateless and homeless, and the ( non-Japanese ) Manchurians wanted to be rid of these foreigners. Many were killed, many others ended up in Siberian prisons for up to 20 years, and some made their way to the Japanese home islands, where they were also treated as foreigners. Manchuria was `` cleansed '' by Soviet forces of any potential military resistance. With Soviet support for the spread of Communism, Manchuria provided the main base of operations for Mao Zedong 's forces, who proved victorious in the following four years of the Chinese Civil War. These military successes in Manchuria and China by the Communist Chinese led to the Soviet Union giving up their rights to bases in China -- promised by the Western Allies -- because all of the land deemed by the Soviets to be `` Chinese '', ( as distinct from what the Soviets considered to be `` Soviet '' land which had been occupied by the Japanese ), was eventually turned over to the People 's Republic of China. Note, however, that before leaving Manchuria, Soviet forces and bureaucracy dismantled almost all of the portable parts of the considerable Japanese - built industry in Manchuria and relocated it to `` restore industry in war - torn Soviet territory ''. That which was not portable was either disabled or destroyed ; the Soviets had no desire for Manchuria to be an economic rival, particularly to the underdeveloped Far Eastern Soviet Territories. However, after the establishment of the People 's Republic of China the bulk of the Soviet economic assistance went to Manchuria to help rebuilding the region 's industry. As agreed at Yalta, the Soviet Union had intervened in the war with Japan within three months of the German surrender, and they were therefore entitled to annex the territories of Karafuto and the Chishima Islands and also to preeminent interests over Port Arthur and Dalian, with its strategic rail connections. The territories on the Asian mainland were subsequently transferred to the full control of the People 's Republic of China in 1955 ; the other possessions are still administered by the Soviet Union 's successor state, Russia. The division of Korea between Soviet and US occupations led to the creation of the separate states of North and South Korea. This was a precursor to the Korean War five years later. See also World War II portal Japan portal Soviet Union portal Mongolia portal China portal Battle of Mutanchiang Battle of Shumshu Military history of Japan Military history of the Soviet Union Kuril Islands dispute Project Hula Gegenmiao massacre Notes Jump up ^ Glantz credits the Japanese with 713,000 men in northern Korea and Manchuria, and 280,000 in southern Korea, Sakhalin, and the Kuriles. Jump up ^ 41,199 is the listed total of Japanese soldiers in Soviet custody on August 19, two days after the surrender of the Kwantung Army by order of Hirohito and four days after Hirohito announced the surrender of Japan. Post-war, 594,000 to 609,000 Japanese soldiers ended up in Soviet custody. References ^ Jump up to : David M. Glantz, `` August Storm : The Soviet 1945 Strategic Offensive in Manchuria ''. Leavenworth Papers No. 7, Combat Studies Institute, February 1983, Fort Leavenworth, Kansas. ^ Jump up to : Glantz, David M. & House, Jonathan ( 1995 ), When Titans Clashed : How the Red Army Stopped Hitler, Lawrence, Kansas : University Press of Kansas, ISBN 0 - 7006 - 0899 - 0, p. 378 Jump up ^ Glantz, David M. & House, Jonathan ( 1995 ), When Titans Clashed : How the Red Army Stopped Hitler, Lawrence, Kansas : University Press of Kansas, ISBN 0 - 7006 - 0899 - 0, p. 300 Jump up ^ G.F. Krivosheev, ed., `` Russia and the USSR in twentieth century wars : A statistical survey ''. Moscow : ' Olma - press ', 2001, page 309. Jump up ^ Cherevko, Kirill Evgen'evich ( 2003 ). Serp i Molot protiv Samurayskogo Mecha. Moscow : Veche. ISBN 5 - 94538 - 328 - 7. Page 41. Jump up ^ Coox, Alvin D. ( 1990 ) ( 1985 ). Nomonhan : Japan Against Russia, 1939. Stanford, California : Stanford University Press. p. 1176. ISBN 9780804718356. Retrieved 9 February 2017. Jump up ^ The Associated Press ( 8 August 2005 ). `` A Soviet Push Helped Force Japan to Surrender ''. The Moscow Times. Jump up ^ Lekic, Slobodan ( 22 August 2010 ). `` How the Soviets helped Allies defeat Japan ''. San Francisco Chronicle. ^ Jump up to : `` Battlefield -- Manchuria -- The Forgotten Victory '', Battlefield ( documentary series ), 2001, 98 minutes. ^ Jump up to : Hayashi, S. ( 1955 ). Study of Strategic and Tactical peculiarities of Far Eastern Russia and Soviet Far East Forces. Japanese Special Studies on Manchuria ( Report ). XIII. Tokyo : Military History Section, Headquarters, Army Forces Far East, US Army. ^ Jump up to : Drea, E.J. ( 1984 ). `` Missing Intentions : Japanese Intelligence and the Soviet Invasion of Manchuria, 1945 ''. Military Affairs. 48 ( 2 ) : 66 -- 73. JSTOR 1987650. ^ Jump up to : Butow, Robert Joseph Charles ( 1956 ). Japan 's decision to surrender. Stanford University Press. Jump up ^ Richard B. Frank, Downfall : The End of the Imperial Japanese Empire, Penguin, 2001 ISBN 978 - 0 - 14 - 100146 - 3. ( Extracts on - line ) Jump up ^ Robert James Maddox, Hiroshima in History : The Myths of Revisionism, University of Missouri Press, 2007 ISBN 978 - 0 - 8262 - 1732 - 5. ^ Jump up to : Tsuyoshi Hasegawa ( 2006 ). Racing the Enemy : Stalin, Truman, and the Surrender of Japan. Belknap Press. p. 298. ISBN 0 - 674 - 01693 - 9. Jump up ^ Soviet Declaration of War on Japan, August 8, 1945. ( Avalon Project at Yale University ) Jump up ^ Maurer, Herrymon, Collision of East and West, Henry Regnery Company, Chicago, 1951, p. 238. ^ Jump up to : Soviet - Japanese Neutrality Pact, April 13, 1941. ( Avalon Project at Yale University ) Jump up ^ Declaration Regarding Mongolia, April 13, 1941. ( Avalon Project at Yale University ) Jump up ^ Soviet Denunciation of the Pact with Japan, April 5, 1945. ( Avalon Project at Yale University ) Jump up ^ So sorry, Mr Sato, April 1945, Time magazine. Jump up ^ Russia and Japan, declassified CIA report from April 1945. ^ Jump up to : Boris Nikolaevich Slavinskiĭ, The Japanese - Soviet Neutrality Pact : A Diplomatic History 1941 -- 1945, Translated by Geoffrey Jukes, 2004, Routledge. ( Extracts on - line ) ^ Jump up to : Jones, F.C. `` Manchuria since 1931 '', 1949, Royal Institute of International Affairs, London. pg. 221 Jump up ^ Robinson, Michael E ( 2007 ). Korea 's Twentieth - Century Odyssey. Honolulu : University of Hawaii Press. pp. 104 -- 105. ISBN 978 - 0 - 8248 - 3174 - 5. Jump up ^ Seth, Michael J. ( 2010 ). A Concise History of Modern Korea : From the Late Nineteenth Century to the Present. Hawaìi studies on Korea. Rowman & Littlefield. p. 86. ISBN 9780742567139. Retrieved 2015 - 11 - 16. Jump up ^ Buzo, Adrian ( 2002 ). The Making of Modern Korea. London : Routledge. p. 50. ISBN 0 - 415 - 23749 - 1. Jump up ^ Hyung Gu Lynn ( 2007 ). Bipolar Orders : The Two Koreas since 1989. Zed Books. p. 18. Jump up ^ Richard B. Frank ( 8 August 2005 ). `` Why Truman Dropped the Bomb ''. The Weekly Standard. 010 ( 44 ). Jump up ^ Hasegawa, Tsuyoshi ( 17 August 2007 ). `` The Atomic Bombs and the Soviet Invasion : What Drove Japan 's Decision to Surrender ? ''. Japan Focus. Jump up ^ Kuramoto, K. ( 1990 ). Manchurian Legacy : Memoirs of a Japanese Colonist. East Lansing, Michigan State University Press. Jump up ^ Shin'ichi, Y. ( 2006 ). Manchuria under Japanese Dominion. Philadelphia, University of Pennsylvania Press. Jump up ^ Tamanoi, M A. ( 2009 ). Memory Maps : The State and Manchuria in Postwar Japan. Honolulu, University of Hawai'i Press. ^ Jump up to : Borisov, O. ( 1977 ). The Soviet Union and the Manchurian Revolutionary Base ( 1945 -- 1949 ). Moscow, Progress Publishers. Jump up ^ M.V. Aleksandrova ( 2013 ) Economy of Northeastern China and Soviet assistance to the PRC in the 1950s Further reading All are in English : Despres, J, Dzirkals, L, et al. ( 1976 ). Timely Lessons of History : The Manchurian Model for Soviet Strategy. Santa Monica, RAND : 103. ( available on - line ) Duara, P. ( 2006 ). The New Imperialism and the Post-Colonial Developmental State : Manchukuo in comparative perspective. Japan Focus. Garthoff, R L. ( 1966 ). Soviet Military Policy : A Historical Analysis. London, Faber and Faber. Garthoff, R L. ( 1969 ). The Soviet Manchurian Campaign, August 1945. Military Affairs XXXIII ( Oct 1969 ) : 312 -- 336. Glantz, David M. ( 1983a ). August Storm : The Soviet 1945 Strategic Offensive in Manchuria, Leavenworth Paper No. 7, Command and General Staff College, Fort Leavenworth, Kansas, February 1983. Glantz, David M. ( 1983b ). August Storm : Soviet Tactical and Operational Combat in Manchuria, 1945, Leavenworth Paper No. 8, Command and General Staff College, Fort Leavenworth, Kansas, June 1983. Glantz, David M. ( 1995 ) The Soviet Invasion of Japan. Quarterly Journal of Military History, vol. 7, no. 3, Spring 1995. Glantz, David M. ( 2003 ). The Soviet Strategic Offensive in Manchuria, 1945 ( Cass Series on Soviet ( Russian ) Military Experience, 7 ). Routledge. ISBN 0 - 7146 - 5279 - 2. Gordin, Michael D. ( 2005 ). Five Days in August : How World War II Became a Nuclear War. ( Extracts on - line ) Hallman, A L. ( 1995 ). Battlefield Operational Functions and the Soviet Campaign against Japan in 1945. Quantico, Virginia, United States Marine Corps Command and Staff College. ( available on - line ) Hasegawa, T. ( Ed. ) ( 2007 ). The End of the Pacific War. ( Extracts on - line ) Ishiwatari, H, Mizumachi, K, et al. ( 1946 ) No. 77 -- Japanese Preparations for Operations in Manchuria ( prior to 1943 ). Tokyo, Military History Section, Headquarters, Army Forces Far East, US Army. Phillips, S. ( 2004 ). The Sino - Japanese War, 1937 -- 1945 : The Military Struggle -- Research Guide and Bibliography. Towson University. available on - line USMCU CSC ( 1986 ). The Soviet Army Offensive : Manchuria, 1945. ( US Marine Corps University, Command and Staff College -- available on - line ) Japanese Monographs The `` Japanese Monographs '' and the `` Japanese Studies on Manchuria '' -- The 187 Japan Monographs are a series of operational histories written by former officers of the Japanese army and navy under the direction of General Headquarters of the U.S. Far East Command. Monographs of particular relevance to Manchuria are : No. 77 Japanese preparations for Operations in Manchuria ( 1931 -- 1942 ) No. 78 The Kwangtung Army in the Manchurian Campaign ( 1941 -- 1945 ) Plans and Preparations No. 119 Outline of Operations prior to the Termination of War and activities connected with the Cessation of Hostilities ( July -- August 1945 ) No. 138 Japanese preparations for Operations in Manchuria ( January, 1943 -- August 1945 ) No. 154 Record of Operations against Soviet Russia, Eastern Front ( August 1945 ) No. 155 Record of Operations against Soviet Russia, Northern and Western Fronts ( August -- September 1945 ) List of the 13 Studies on Manchuria Vol. I Japanese Operational Planning against the USSR ( 1932 -- 1945 ) Vol. II Imperial Japanese Army in Manchuria ( 1894 -- 1945 ) Historical Summary Vol. III STRATEGIC STUDY ON MANCHURIA MILITARY TOPOGRAPHY AND GEOGRAPHY Terrain Study Vol. IV AIR OPERATIONS ( 1931 -- 1945 ) Plans and Preparations Vol. V INFANTRY OPERATIONS Vol. VI ARMOR OPERATIONS Vol. VII SUPPORTING ARMS AND SERVICES Vol. VIII LOGISTICS IN MANCHURIA Vol. IX CLIMATIC FACTORS Vol. X Japanese Intelligence Planning against the USSR ( 1934 -- 1941 ) Vol. XI Small Wars and Border Problems Vol. XII Anti-Bandit Operation ( 1931 -- 1941 ) Vol. XIII Study of Strategic and Tactical peculiarities of Far Eastern Russia and Soviet Eastern Forces ( 1931 -- 1945 ) External links Wikimedia Commons has media related to Soviet -- Japanese War ( 1945 ). 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Question: when did the soviet union declared war on japan and invade manchuria
Answer: August 9, 1945