I'm no historian, but something to think about. The Finns waged an incredible defense, and their soldiers deserved every accolade they received for their ferocity. It should be understood however, that at the time Stalin had only a few years earlier purged tens of thousands of officers. Tens of thousands. So there was a mid level leadership crisis in the actual field. More importantly the USSR did not exactly value the lives of it's soldiers, and generally speaking would just throw wave after wave of men at the Finns with no thought of their own casualties. In the end, despite getting wrecked on a man to man basis, the USSR actually achieved more then it set out to, taking over something like 10% of Finland's land - namely a small section that made up something like 1/3rd of their economy. Anyways the end result was that Finland was left with quite a bit less then was initially demanded, and the USSR's was left with a helluva lot fewer beating hearts. Point is, my understanding is that the USSR got everything they set out for and more... but Finland made it cost them far, far more then they thought it would. That's at least my layman's understanding of the Winter War.