My uncle was left behind with troops in WW1 in vladivostock russia after the war ended?

After Soviet Russia declared a separate peace with Imperial Germany, the remaining allies sent troops to Vladivostok, Archangel and Murmansk under the pretense of guarding Allied munition stocks which remained there. The venture was the idea of the British Minister of Munitions, Winston Churchill. The allies did not disengage their troops from these three areas until early to mid-1919. To get more information, merely enter the term "Archangel-Murmansk Intervention" into your search engine.