The Soviet-Japanese War

In 1938, Japan launched an attack on the USSR. The Japanese then lost to the Soviets at the Battle of Lake Khasan. The Japanese launched another invasion but were defeated by the Soviet Army again. What if the Japanese won the Battle of Lake Khasan, allowing it to keep Soviet claimed territory in Manchuria?

The Battle of Lake Khasan
Before the Battle of Lake Khasan Japan and the USSR disputed the Changkufeng Heights, which was high ground near Lake Khasan, the city of Najin, and strategic railway systems connecting Manchuria with Korea. On July 6, Soviet soldiers were sent to occupy the heights, which were un-occupied at the time. On July 15, Japan demanded Soviet troops be withdrawn from the heights. The Soviet Union rejected the demand. On July 29, Japan sent soldiers to take the Changkufeng Heights. They were repelled but on July 31 Japan succeeded and Soviet soldiers were forced to retreat from the heights. On August 2 Soviet soldiers were ordered to reclaim the heights. In OTL the Soviets forced Japan out of the heights ending the Battle of Lake Khasan and the first border war between Japan and the USSR. But in ATL Japan manages to repulse Soviet soldiers ordered to take the heights.

The Soviet Union, not wanting to give up the heights, ordered another attack on the heights. Once again the Soviet soldiers were repulsed. Japanese forces under Colonel Kotoku Sato were ordered to counter-attack against Soviet soldiers at Bezymyannaya Hills, which was near the Soviet-Korean border. The Soviets repusled the attack as reinforcements came to them because Vladivostok was not far from the Hills. The Japanese launched another attack but were repulsed again. By now war between the Soviet Union and Japan was likely. On September 2, the Soviet Navy at Vladivostok bombared Korean coastal cities. Japan considered that an act of war and on September 4 Japan and the Soviet Union declared war on each other. Because Japan was a member of the Anit-Comintern Pact Germany and Italy declared war on the Soviet Union as well.

The War
The Soviet-Japanese War was the name given to war, however, more sides were involved.

Sides:

Soviet Coalition

USSR

Britain (following the Baltic Sea Incident)

Finland

Anti-Comintern Pact

Empire of Japan

Germany

Italy

The War Begins
After intialial declarations of war the Japanese Navy under the command of Isoroku Yamamoto and the Soviet Union engaged in naval clashes near Vladivostok. Japan hoped to gain superiority in the sea so it could launched an amphibious assault on Vladivostok. The Japanese Army Air Force, specificly the Second Air Army began bombing Vladivostok and attempted to gain air superiority over Soviet airplanes in the area. While that was happening the Japanese 75th Infantry Divison and the 19th Division under Sato launched a third attack on Bezymyannaya. Japan managed to gain the hillls this time an launched an attack on Mount Kholodlilnik, which overlooked all of Vladivostok. The battle there was bloody and Japan was repulsed at the end. After that Sato had his divisions regroup to the south of the mountain.

In the Baltic Germany launched an attack on the Estonia, Lativia, and Linthuania in March 1939. German paratroopers led by Kurt Meyer stormed the countrysides while the Luftwaffe bombed important cities. The attack on these countries was led by Gunther von Kluge. These countries fell in by April. Germany then launched an attack on Finland. Finland managed to hold off German atttacks but its southern half was overtaken by June. The southern half of Finland was turned into the German sattlite state of the Finland Socialist Republic. The northern half remained in Finnish hands however. The Soviet Union also attack into the FSR in an attempt to take the land for itself.

Britain at first did not do anything as it did not want war with Germany. Britain was also under Neville Chamberlain at the time. However, Germany sunk a British ship heading to Finland as it believed it was giving Finland supplies. As Britain wanted war with Germany Chamberlain resigned as he believed in order to win the war a government supported by all parties was essential, and Winston Churchill took office.

The War Continues
The war was still going on by 1940. Kotoku Sato was given the 23rd Division along with the 75th Division and the 19th Division he already commanded and was ordered to take Mount Kholodlilnik at all costs. Sato ordered the 64th Regiment under Colonel Takemitsu Yamagata of the 23rd Division to launch a diversionary attack on the western side of the mountain while the rest of the 23rd Division and the 75th and 19th assaulted the mountain on the southern side. The attack worked and the Japanese made there way up the mountain. The Soviet defenders there led by Ivan Konev dug bunkers and trenches so the Japanese had to dig them out one by one. In order to help in the attack the Second Air Army was ordered to bombard the mountain. The planes used poison gasses such as mustard in order to make the Russians get out of their bunkers and trenches. After the bombing a handful of Russian soldiers were dead and Sato continued his attack. Reinforcements arrived for the Russians; the 39th Rifle Corps under Grigori Shtern. After 20 days of fighting the Russian reinforcements forced Sato off the hill. Russian soldiers then fought Sato's units near the hill.