As a result of her victories in the wars against China (1894–95) and Czarist Russia (1904–05), Japan secured the basic elements of her national desires—for the time being. Afterwards she undertook the management of Manchuria. This marked the first step in Japan's policy of developing of the Asiatic continent and of striving for racial expansion (see Empire of Japan, imperialism in Asia).
By their very success, the major developments in national policies greatly enhanced the already dominant role of national defence in politics. They took place in an atmosphere of tension between the Imperial Japanese Navy and Imperial Japanese Army, which was unresolved in the period under discussion. The Army became associated with strategic planning for mainland Asia, namely forward planning for Asian land wars; and the North Strike group.
See also Japanese strategic planning for the Pacific (1905-1940) for the Navy's concept, and the South Strike group.
The main objective of national defence policy centered upon the presumption of a potential enemy. Since the first plan of 1907 the primary foe was judged to be Tsarist Russia, it was presumed that Russia would be seeking revenge for the defeat during the 1904-1905 war. However, the years following new national defense policy, witnessed remarkable changes in the international situation; the fall of Russian Empire in 1917 and birth of the Soviet Union in 1922, the powerful American influence in the Far East and the Japanese exclusion movement within the United States itself.
From this point the Army concentrated upon strengthening the defenses of Manchukuo, with a view of the Soviet Union as a hypothetical primary enemy of Japan. In the event of a war with Soviet Union, military operations had originally been predicated upon a defensive struggle for vital North Manchuria, in two important sectors: the plains region between Harbin and the Upper Sungari River (which flows between Hsinking and Harbin); and the plains between Taoan and Tsitsihar. In early summer of 1923, however, the Soviet Army began to erect "tochika" (Japanese for tochka, frontier pillbox) positions along the frontiers opposite the border forts which the Kantogun then proceeded to build.
The idea of launching an eastern offensive was first conceived at the time of the new plan of 1934. Three years later Japanese operational planning was again revised:
In devising operational plans against the USSR, the hypothetical movements of the Soviet Far Eastern Army were a major consideration. The Japanese Army General Staff made the following estimate of the situation: the Soviets could be expected to commit 55-60 divisions to the Far Eastern Operations. They would launch simultaneous, converging offensives from the east, north and west of Manchuria. The enemy would strive to cut off communications between the Japanese homeland and the Asiatic continent. If a war broke out with the Soviet Union, the most important problem would arise: how to terminate the hostilities? The Army General Staff feared that the Russian territory was so boundless that Japan would be unable to deal a finishing blow to the enemy.
Within the Army, the prevailing and expert opinion concerning the solution to this trouble was to employ subversion; in other words the Army therefore placed as much importance upon "political sabotage" as did upon field operations, in planning for hypothetical operations against the Soviet Union. These measures were designed to counter Soviet activities as well as to foster Japan's own strategic ends. The program was accelerated after Japanese troops reached the Soviet frontier subsequent to the Manchurian incident in 1931, and constituted a prime consideration of the Kantogun Intelligence Section.
The idea was to use the White Russians, Koreans, Chinese, Mongols, Buriats and others living there. Important to anti-Stalinist and anti-Soviet doctrine was the knowledgeable defector General Lushkov of the NKVD, together with other Russian ex-Soviet officers then in the service of Japanese Army intelligence. Principally responsible for Mongol, Buriat and other North Asian agents was Lieutenant General Kanji Tsuneoka, for whom the Kantogun established the "Central Academy" in Kalgan, Mengjiang. Mongol saboteurs and agitators during the late 1920s and early 1930s provoked some disorder in the Western area of Outer Mongolia, suppressed by the Russian and Mongol authorities; this was possibly under his orders. He was a North Asian expert and studied in depth the issue of controlling Central Asia.
Japanese military experts placed weight on the experience during Russo-Japanese war of 1904-1905 when Colonel Motojiro Akashi had used subversion. His tactics of contacting in Europe all the opponents of the Czarist rule — Zilliakus and Plekhanov, as well as nationalists — was considered to have undermined the Russian state and was cited as a brilliant example of "political sabotage".
The failure of certain attempts at subversion in 1938 was later attributed to the exaggeration of the struggles of minorities within the USSR - the recurrent theme of the "Confrontation of Races", as well as to the overconfidence of agents. Japanese military missions in Germany received information of Nazi schemes of political subversion too, particularly being interested in the attempts by the Abwehr and Brandenburg unit to make use of Ukrainian and other Slavic Eastern minorities. They were in close touch with White Russian émigrés in Germany. Other Japanese reports mentioned similar comments recovered from a Serbian Communist residing in Siberia on the resentment of the whole Siberian population towards the Soviet central authorities: their sense of being treated as second class citizens; how the workers liked to take weapons for a new and just social revolution; how students would bet on the alternatives of German Nazi or Japanese Victory over the Soviets in Siberia; and how local politicians discussed secretly collaboration with the Axis powers in case of a defeat of the Stalinist government.
The main objective of the Imperial Army would be to build up to the strength necessary to occupy all the Maritime Province and Sakhalin Island, while at same time securing Manchuria and occupying exterior Mongolia and the Lake Baikal. Other probable objectives added to the basic war plan were a possible invasion of Irkutsk-Krasnoyarsk (East-Central Siberia), and/or an incursion to occupy Central Asia mainland.
After this secret conference, Imperial Headquarters ordered the implementation of the revised policy toward the Soviet Union by commencing large scale reinforcements of the Kantogun. To keep the true reasons secret, the build-up was called the "Special Manoeuvers of Kantogun" or Kantokuen for short. The 400,600 troops of the Kantogun suddenly rose to over 700,000 and some billion Yen in military funds were allocated. These manoeuvres prepared the use of force against Soviet Union, based upon the prospect that the Russo-German war might rapidly take a favorable turn for Germany. In the event that force was used against the USSR, the new operational plan of 1939 was scheduled to go into effect, whereby simultaneous offensives were to be mounted north and east from Manchuria. Additionally the new plan included landings in Soviet Far East islands and coastal areas, and land operations in Outer Mongolia. Japan also had in Manchuria 150,000 to 200,000 troops.
The Imperial Army anticipated the German offensive to commence in 1941-42. The Russians had to transfer several divisions from the Far East to European sectors, but the USSR would never leave Siberia defenseless, even if the war with Germany turned badly for her. It was thought to be almost beyond the realm of possibility for the Soviet Union to participate in a war between Japan and United States, of her own accord, thereby having to wage two-front operations. Certain reports mentioned the sending of 20 or 30 divisions to the European battlefront.
Although the Kantogun had been reinforced, the Russo-German War for which the Japanese Army had held such great expectations might not turn out favorably for Germany, despite Hitler's boasts. A serious problem consequently demanded response: how could the expanded Kantogun pull through the rigorous cold of a Manchurian or Siberian winter? Military materiel was geared to hypothetical mobile operations against the Soviet Union, characterized by light weapons, large scale logistical systems, light armored groups and many horses. If after the southern operations are underway, the Soviet Army appeared to be mounting an invasion of Manchuria, requisite forces could be diverted there in ample time.
As defensive measures against any Soviet counteroffensive, Japan had the primary goal of knocking out the Soviet Far Eastern Air Forces, as necessary to protect Manchuria and Japan. The Kantogun laid plans for a border defense system in 1934, but construction work did not begin until 1935. To begin with, to 1938 only four zones were fortified in East Manchuria, plus three in the north and one in the west.
The Soviet Far East Front (official name of the relevant military district) was under the Red Flag Special Army from 1929. This army was divided into First and Second Red Flag Army during 1938. These forces had 450,000 to 600,000 armed soldiers; other sources mention 225,000 men, 5,000 tank pilots and 15,000 frontier guards for a total of 290,000 or 840,000 units.
The regular Soviet division always counted as 20,000 soldiers. In the Baikal region are estimated to have been 630,000 men, 3000 aircraft, and 2,300 armored vehicles. The Soviet government funded construction of 4,000 defensive fortifications on the Manchukuan-Soviet frontier.
The Soviet Air Force in the Russian Far East had airbases in Chita, Blagoveshchensk, Khabarovsk, Komsomolsk-on-Amur, Nikolayevsk-on-Amur, and other sites. It is supposed that these sites were heavily armed, with anti-aircraft guns and fortified positions, as was the case for the Moscow and Leningrad defenses.
The Soviet Pacific Fleet is estimated at 100 or more vessels. According to one source, in 1938-39 this fleet consisted of 18 destroyers, 90 diesel submarines, 80 coastal patrol boats, 30 gunboats, 75 armored light boats (mosquito boats), with bases in Nikolayevsk-on-Amur, Vladivostok, Ohkostk, Nagayevo, Petropavlovlsk-Kamchatsky, Komsomolsk-on-Amur, and Khabarovsk. Also 60 "shark" boats, 42 other submarines, and river patrol boats. Others preparations were the construction of the Amur-Baikal railway, industrial development in the Baikal area and the rapid production from Zabaikalsk and Konsomolsk factories of 1,000,000 tonnes of steel per year, for a prolonged war in the Soviet Far East.
During the war with Germany, Pacific naval personnel built and fortified Soviet naval bases. The navy was stripped of many sailors who were sent to fight on the front in the west. In 1943 the Soviet Pacific Fleet trained for amphibious and combined operations.
The continuing border wars between Bolshevik, White Russian, Chinese Japanese, Local Manchu Agents and bandit forces led the Soviets to deploy most of their small inventory of refurbished Renault FTs Tanks on the Manchurian border in the mid-1920s. During the fighting Japanese and Manchu agents with the Soviets over the Chinese Eastern Railway in the autumn of 1929 the Soviets brought up a company of MS-1 (T-18) light tanks to counter the Japanese FT-1 Renaults, but a tank-vs-tank confrontation never materialised.
On September 18, 1931, some provocateurs (in fact Japanese special forces), purportedly in the Japanese official version Russian or Chinese "bandits", began armed aggressions in the Litiaokou area, near Mukden. The Kwantung Army HQ was located at Port Arthur, and the garrison troops consisted of one main infantry division and six battalions of independent garrison units (with detachment in Mukden).
Existing treaties provided for no more than seventeen railway guards per kilometer and the total strength of the Kantogun at this time amounted to only 10,400 troops.
On September 19 the Japanese Government, which had decided upon a policy of localizing the incidents, communicated its decision. Despite this, the Kantogun rapidly proceeded to expand its operation, and in the next five months had seized most the principal cities and towns throughout Manchuria.
This is called also the "Mukden incidents" (the Japanese invasion of Manchuria), leading to Japanese control there. (This was not, naturally, a Japanese-Russian combat, but a preliminary move by Japan.)
In this armed confrontation, the Japanese 19th Division from Chosen (Korea) took on at least two Soviet infantry divisions, in a territorial dispute between Japan and Manchukuo on the one hand, and the USSR on the other. It is also known as the Lake Khasan Incident, for the lake of the same name in the area, which is the conventional title.