We desperately need to destroy military and economic potential opponent on the Don river. The Germans and Americans support Russians. 

We have a severe Russian winter, hence the lack of support ally of Japan.
We need to resolve the battle in our favor. From now on, failure is unacceptable and will result in a change of strategic goals or even inaction. The Germans and the Americans supports the Russians, so General, You must to demonstrate talent.
We need this victory and economic resources on the Don river to continue attack to the East.