If this White Russian state joins the Allies in WW2, then it will drastically change the politics of the Far East. It gives the US a base to stage an invasion of Manchuria, preventing a Russian invasion. This will place Manchuria in the hands of pro-USA capitalists. It will also prevent the creation of North Korea. A pro-USA Manchuria might give Chiang the edge he needs to defeat Mao, since it give the USA a vested interest in giving him more aid and also grant Chiang the use of Manchurian heavy industry. If Mao is still victorious, Manchuria may remain an independent state. This White Russian state is also located on the Soviet's only major Pacific port. This is going to make the cold war in Asia far easier. Without Soviet aid, an American victory in Vietnam would definitely be possible, even with China still being communist. If they aren't, an American victory is assured.