I've been reading a very interesting Alternate History timeline on a board I participate in http://www.alternatehistory.com this website is really intruiging for people who are interested in history and thinking about how things could have gone the other way.
The TL (timeline) is called "Storm in the East v2.0: The Second Russo Japanese War"
The thread starts off with an explanation of the Soviet and Japanese head butting in the Far East over territory, especially around Mongolia. The author (sreen name The Red) explains how each side was constantly skirmishing over the border territory and how tensions were always high. the POD is interesting as it revolves the battle of Khalkhin Gol getting out of hand and escalating into a full scale war. The battle is a great Soviet victory (more so than OTL- Our Timeline) which makes Stalin decide to exploit it by sending in more soldiers and thus widening the war.
This results in a general invasion of Manchuria with the Soviet aim being to conquer the region and absorb it into the USSR. It gets off to an excellent start fast and does a wonderful job of comparing the two military doctrines of the opposing sides. For instance the Japanses are relatively defenceless against Soviet tanks, their own tanks being designed to fight against infantry. It also shows how the Japanese were not used to having to fight an enemy with firepower equal to their own. The Soviets on the other hand have communications problems, bumbling officers and are struggling to obtain supremacy in the air as superior Japanese planes and pilots whittle them down. The biggest difference between the two sides is that the Soviets can afford higher losses, the Japanese cannot.
It also gives the Soviets more experience on all levels of command and strategy. This should prove to be valuable as the TL progresses into WW2 where Hitler is going to face a Red Army that is much more competent than he is expecting...
It makes for a good read and there are many others like it on the site. I highly encourage readers to check it out.