It's a very complicated set of triggers but here's the gist: You can win this scenario by taking at least two of the four other primary VP's and then Moscow but it must be done quickly and therefore I believe it to be next to impossible.
When you capture the two primary VP's, fulfilling "Capture and hold 2 Primary VPs," the scenario requires you to keep them for three turns while the mission becomes "Do not lose any Primary VPs." You can still capture Moscow during that time.
After three more turns, however, the "Capture Moscow" objective is turned off, as is "Do not lose any Primary VPs," and the primary mission becomes merely "Do not lose any Secondary VPs." Which you can still achieve by not doing so until the end of the scenario. Thus a scenario victory is achievable even though you lost the primary VP's and never took Moscow.
It's a rather ingenious way of allowing the player to win even though gameplay goes the same way as history. So again, while you can win this scenario by blitzing through to Moscow, it must be in the early turns or not at all. I'm not OOB's best player by far but it was my impression that unless you are playing on a very low level of difficulty, you really are not supposed to win in that fashion.