Nice map, great idea! And scary... I guess WW2 begins with tanks rolling into Poland... and they keep right on going into the USSR...

The only thing that I'd change is minor - you have lat/long lines, and the text follows them to a certain extent, but especially with the USSR's label, it looks odd that the text doesn't curve to follow the lines. I'd either leave all the labels strictly horizontal or curve them to match the lines; otherwise (to me, anyway) it makes the labels look 'crooked'.