In 1919, taking advantage of the weakness of Russia's government caused by revolutions and civil war, the Chinese government, established by members of the Anhui military party, sent troops led by Gen. Sui Shuzheng to join Outer Mongolia to China and end itsd autonomy.
After Kolchak's defeat at the hands of the Red Army and the subsequent decision of Japan to withdraw its expeditionary troops from the Transbaikal, Semyonov, unable to withstand the pressure of Bolshevik forces, planned a retreat to Manchuria.