(Sorry for the dark picture.)
After the end of WWI the United States struggled to find its place in the world. Still largely an isolationist nation, we had come out of our shell in a major way by sending troops to the fields of France. The Entente powers ended up winning the war against Germany, but something more interesting was happening in Russia which would test America’s new role in the world.
In October 1917 the communist forces came to power in Russia during the Bolshevik Revolution and immediately signed a treaty with Germany. This freed up many resources for the Germans and placed the outcome of the war in doubt. Russia was gripped in a terrible civil war as the Bolsheviks and Tsarists battled for the soul of their country.
The Allies had other issues besides the massive reinforcements the Germans were looking to throw their way. First off they had spent a lot of money and sent a lot of supplies to the Russians during the war, and no one wanted any of that to fall into the hands of the Communists. Second, all 50,000 Czechoslovakian troops were stuck in Russia, and were being attacked. They had one way out and that was through Vladivostok in Siberia. So the allies had to do something and the decision was made to intervene in the Russian Civil War on the side of the Tsar. England and France were tapped out for resources, so it was decided the US would lead the way.
In July 1918 President Wilson ordered 5,000 men to North Russia (The Polar Bear Expedition) and 10,000 to Siberia (The Siberian Expedition) with the mission to secure whatever war materials they could from the communists, and to help facilitate the evacuation of the Czech troops. As part of the expedition Imperial Japan occupied part of Siberia and China sent several thousand troops. The occupation ended in June 1920 when the Allies felt they had accomplished their goals, the Japanese however stayed untill​ 1922.
The uniform in the picture belonged to First Lieutenant Verner C. Aurell of the 27th Infantry Regiment, “The Wolfhounds” served in the expedition until April 1920. A very interesting artifact from the time the US invaded, and occupied Russia.