The Soviet invasion of Manchuria or Manchurian Strategic Offensive Operation (Russian: Советско-японская война), began on August 9, 1945, with the Soviet invasion of the Japanese puppet state of Manchukuo. The Soviets conquered Mengjiang, as well as northern Korea, southern Sakhalin, and the Kuril Islands. The operation is sometimes called Operation August Storm by English-language writers, after historian David Glantz used this title for a paper on the subject.
At the Yalta Conference, the Soviet Union had agreed to Allied pleas to terminate its neutrality pact with Japan and enter World War II's Pacific Theater within three months after the end of the war in Europe. This offensive should not be confused with the Soviet-Japanese Border War that ended in Japan's defeat in 1939.
The invasion began at dawn on August 9, 1945, precisely three months after the German surrender on May 8 (May 9, 0:43 Moscow time). This fell between the atomic bombings of Hiroshima on August 6 and Nagasaki on August 9. However, it is clear that news of the attacks on the two cities played no role in the timing of the Soviet attack. Although Soviet leader Joseph Stalin had not been told much detail of the Western Allies' atomic bomb program by Allied governments, he was nonetheless well aware of its existence and purpose by means of Soviet intelligence sources.
The operation was subdivided into smaller operational and tactical parts:
The Transbaikal Front would form the western half of the Soviet pincer movement, attacking across the Inner Mongolian desert and over the Greater Khingan mountains. These forces would secure Mukden (present day Shenyang), and meet troops of the 1st Far East Front at the Changchun area in south central Manchuria and in doing so finish the double envelopment.
Amassing over one thousand tanks and self-propelled guns, the 6th Guards Tank Army would serve as armored spearhead leading the Front's advance and would have to capture objectives 350 kms (217 miles) inside Manchuria by the fifth day of the invasion.
The 1st Far East Front would form the eastern half of the pincer movement, attack which would involve the 1st Red Banner Army, the 5th Army and the 10th Mechanized Corps striking towards Mudanjiang (or Mutanchiang). Once that city was captured, this force would advance towards the cities of Jilin (or Kirin), Changchun and Harbin. Its final objective would be to link up with forces of the Transbaikal Front at Changchun and Jilin (or Kirin) thus closing the double envelopment movement.
As a secondary objective, the 1st Far East Front had to prevent Japanese forces from escaping to Korea and then invade the Korean peninsula up to the 38th parallel, establishing in the process what would later become North Korea. The secondary objective would be carried out by the 25th Army. Meanwhile, the 35th Army was tasked with capturing the cities of Boli (or Poli), Linkou and Mishan.
|Total||Transbaikal Front||1st Far East Front||2nd Far East Front|
|Multiple rocket launchers||1,171||583||516||72|
|Tanks and self propelled guns||5,556||2,416||1,860||1,280|
Each Front had "front units" attached directly to the Front instead of an army . The forces totaled at least eighty divisions with 1.5 million men, over five thousand tanks and self propelled guns (including 3,700 T-34s), over 28,000 artillery pieces and 4,300 aircraft (including 3,700 first line combat 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.
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. Korea, which would have been the next target for the Far East Command, was garrisoned by the Seventeenth Area Army.
The Kwantung Army had over six hundred thousand 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; they only had 50 first line aircraft). The Imperial Japanese Navy contributed nothing to the defense of Manchuria, the occupation of which it had always opposed on strategic grounds.
On economic grounds, Manchuria was worth defending since it had the bulk of usable industry and raw materials outside of Japan and still under Japanese control in 1945. However, the Japanese forces were far below authorized strength, and most of their heavy military equipment and best military units had been transferred to the Pacific front over previous three years. As of 1945, the Japanese army in Manchuria contained a large number of raw recruits. As a result, the Kwantung Army had essentially been reduced to a light infantry counter-insurgency force with limited mobility and experience. In the event, Japanese forces were no match for the mechanized Red Army, with its vastly superior tanks, artillery, officers, experience and tactics.
Compounding the problem, the Japanese military made several major mistakes.
New plans made by the Japanese in the Summer of 1945 called for the borders to be held lightly and delaying actions fought while the main force would hold the southeastern corner in strength (so defending Korea from attack). However, the new plans were not implemented by the time the Soviets launched their attack.
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 Japanese commander was missing for the first eighteen hours of conflict, and communication was lost with forward units very early on. 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.
After a week of fighting, during which Soviet forces were already penetrating deep into Manchukuo, Japan's Emperor Hirohito read the Gyokuon-hōsō on August 15, 1945 and declared a ceasefire in the region the next day. The Soviets continued their largely unopposed advance, reaching Mukden, Changchun and Qiqihar by August 20. At the same time, Mengjiang was invaded by the Red Army and their Mongol allies, quickly taking Guihua. The Emperor of Manchukuo (and former Emperor of China), Puyi, was captured by the Soviet Red Army.
On August 18, several amphibious landings had been conducted ahead of the land advance: three in northern Korea, one in Sakhalin, and one in the Kuril Islands. This meant that, in Korea at least, there would already be Soviet soldiers waiting for the troops coming overland. In Sakhalin and the Kurils, it meant a sudden and undeniable establishment of Soviet sovereignty.
The land advance was stopped a good distance short of the Yalu River, the beginning of the Korean peninsula, when even the aerial supply lines became unavailable. The forces already in Korea were able to establish a bit of control in the peninsula's north, but the ambition to take the entire peninsula was cut short when American forces landed at Incheon on September 8, six days after the signing of the Japanese Instrument of Surrender.
Hokkaidō was never invaded as planned.
Japan's decision to surrender was made before the scale of the Soviet attack on Manchuria, Sakhalin, and the Kurils was known, but had the war continued, the Soviets had plans to invade Hokkaidō well before the other Allied invasion of Kyushu.
Tsuyoshi Hasegawa's research has led him to conclude that the atomic bombings were not the principal reason for capitulation. Instead, he contends, it was the swift and devastating Soviet victories on the mainland in the week following Joseph Stalin's August 8 declaration of war that forced the Japanese message of surrender on August 15, 1945. His claim, however, has been criticized because it ignores the fact that the Imperial Headquarters in Tokyo knew that a full-scale invasion had begun but were unaware of how badly the fighting in Manchuria was going.
Manchuria, cleansed of any potential military resistance by Soviet forces, provided the main base of operations for Mao Zedong's forces, who proved victorious in the following four years of civil war in China. In fact, military success in Manchuria prevented the Soviet Union from receiving bases in China — promised by the Western Allies — because all land gained was turned over to the People's Republic of China after they gained power. Before leaving Manchuria, however, Soviet forces dismantled its considerable industry and relocated it to restore industry in war-torn Soviet territory.
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 the territories of Sakhalin and the Kuril Islands and also to preeminent interests over Port Arthur and Dairen, with its strategic rail connections. The territories on the Asian mainland were transferred to the full control of the People's Republic of China in 1955, and the other possessions are still administered by the Soviet Union's successor state, Russia. Though the north of the Korean peninsula was under Soviet control, the logistic machine driving the invasion forces had given out before the entire peninsula could be seized. With the American landing at Incheon — some time before the Red Army could have remobilized and secured the entire nation — Korea was effectively divided. This was a precursor to the Korean War five years later.