The White Army (anti-Bolsheviks / pro-Tsarist forces) had lost, and with their civilian White Movement people, had dispersed to a number of cities, including Harbin. At that time, Manchuria in general, and Harbin in particular, had become sanctuaries for Jews fleeing the pogroms in the Russian Empire (Pale of Settlement area). Ironically enough, the White Army was one of the major perpetrators of pogroms at the time. My family, being Jews of Ukrainian extraction, emigrated out shortly after they arrived. They took a circuitous route through Japan, Kamchatka, and Canada, and arrived in the US just in time for prohibition. Great grandfather found work building stills for the gangsters.

On a side note: The Harbin Jewish population didn't really crash until the second Sino-Japanese war in the 1930's. I'm not going to get into the details, but look up the Defense of Harbin and the Rape of Nanking. it was pretty much a TEOTWAWKI event. All the ammo and booze you could carry was worth less then a safe passage out.