The whole point of the plot, and the irony, is that by allowing the Empire to win over and over again, against all odds, Tanya actually prolonged the war well beyond what it should have lasted, even though he/she wants to war to end quickly. Because the rest of the world is terrified that an Hegemon will appear in not-Europe.
So not-Russia, not-England and not-USA eventually join the war because they feel threatened by the Empire, thus prolonging the war.
But Tanya keeps winning, because Being-X keeps on pushing her.