You could have an independent Xinjiang, if Sheng Shicai took another decision in 1941.
On November 26, 1940, Sheng Shicai concluded an agreement granting the USSR additional concessions in the province of Xinjiang for fifty years, including areas bordering India and Tibet. This placed Xinjiang under virtually full political and economic control of the USSR, making it part of China in name only.
By 1942, Sheng Shicai switched his allegiance to the Kuomintang after major Soviet defeats at the hands of the Germans in World War II, all Soviet Red Army military forces and technicians residing in the province were expelled. In September 1943, Sheng ordered the arrest and execution of the Chinese communists. Among them was Mao Zemin, Mao Zedong's younger brother.
With the Soviet gradual withdrawal, the Kuomintang representatives and personnel filled the void. In October 1943, the Kuomintang effectively removed Soviet influence from Xinjiang. But after the Battle of Stalingrad, Sheng secretly tried to return to the pro-Soviet policy. Stalin, however, refused to intervene and left Sheng at the mercy of the Chinese government, which engineered his removal from office.
ITTL
On 27 July 1942, Sheng Shicai met Dekanozov, former Soviet ambassador to Nazi Germany and Vice Commissar of the Ministry of Foreign Affairs of the USSR in Ürümqi, in order to announce his decision to rejoin the KMT. To the Soviets, who were desperate to retain the oil reserves at Dushanzi and the ores of Xinjiang, this decision represented future difficulties (OTL).
Unlike OTL, Sheng Shicai is convinced not to break his allegiance to Soviet Union after long negotiations and alleged revelations about his brother’s murder (ITTL). After this reunion, Shang Shicai sends a letter to Molotov offering to incorporate Xinjiang into USSR as its 18th Soviet Socialist Republic and asking Stalin for the post of ruler of the new Soviet Republic in exchange of a monopoly over Xinjiang trade and the exploitation of its rare materials and oil.
(IOTL, this letter was sent after the Battle of Stalingrad and the idea was refused by Stalin).
Russian historians consider that Stalin's August 1942 reply, although surprising, must be placed in the context of the siege of Stalingrad. The fear of losing control of the city and the oil fields of Baku certainly motivated the dictator's positive response. For them, Stalin's choice was not to annex Xinjiang formally, but rather to prevent the loss of increasingly strategic resources. On opposite side, Chinese historians view this unlawful annexation as an early proof of Soviet imperialism.
A few months later, the Soviet Union began to send more equipment and secretly reinforced the small forces of Soviet troops quartered in Hami for this end. During the next year, Xinjiang received aircraft, equipment for aviation, rifle-machine-guns and artillery workshops, uniforms, personal supplies, and other military equipment, alongside fresh Soviet troops.
On 1st September 1943, Shang Shicai ordered the arrest of the Kuomintang personnel and formally called Soviet Union for protection against a alleged coup d’état by KMT elements. A day later, four divisions of the NRA New 2nd Army commanded by Zhu Shaoliang were transferred to Xinjiang from Gansu.
Unable to use the destroyed railways, NRA officiers decided to separate the four divisions into four independent columns that would converge to Urumqi.
Those troops were continuously harassed by cavalry units and easy targets for Sheng Shicai’s new bombers.
Those air raids, regularly turned the columns into fleeing masses and officers could barely be obeyed by terrified soldiers intoxicated by the use of mustard gas.
Their morale usually collapsed, when large autonomous units of BA-10 armored cars appeared in the horizon.
Similar units, made of armored cars and tankettes, nicknamed the "Xinjiang wolves" also played a major role during the PRC-Xinjiang border conflicts of the sixties.
Three of the NRA divisions, plagued by desertions, surrendered before the entrance of Soviet troops in Xinjiang. The last division, made of Hui cavalry troops, was annihilated 500 km from Kashgar.
On 13th October, Soviet Red Army troops backed by air units and armored regiments entered into Xinjiang responding to the request of Sheng Shicai.
To this day, the sides blame each other for the start of the conflict. However, a scholarly consensus emerges that the Xinjiang crisis was a premeditated act of violence orchestrated by the Soviet side. After sporadic battles, the last NRA troops had to leave Xinjiang in January 1944 under pressure of the allied leadership that feared a violent KMT-Soviet conflict before Axis defeat.
Xinjiang was formally incorporated into Soviet Union in 1945, which led to the first PRC-Soviet split that took place immediately after the proclamation of the People’s republic of China with the expulsion of Soviet advisors.
To be continued, if you wish ...
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