The Nazis already regard the Russian as "Undermenchen" and treat their prisoners like animals, so there's no hope that they'll treat your prisoners nicely even if you do.
How the enemy treats your captured soldier is not really the most important issue here. What is more important is that if
you mistreat
your prisoners, knowledge of it will eventually reach the ears of the enemy soldiers, and then they will be less likely to surrender.
And that is a very bad thing to happen. In a normal war, only a small percentage of soldiers are really prepared to fight until death. Most soldiers will either retreat or surrender rather than face certain death. You want that as many of them as possible choose the surrendering option as quickly as possible. Everything that you do that makes the enemy fight longer before surrendering will increase your own casualties in the long run.
So do you 1) Do nothing thereby further endangering not only Russia, but the entire civilized world, or 2) Torture him in order to obtain information about troop placements, axis of attack etc.
If this is to be a realistic example, the captured officer will not have enough information for the Soviets to win the whole war based on it. (For example, in 1943 the Soviets had complete plans of Operation Zitadelle for months before the attack date but still the Germans almost managed to break through).
How many captured officers do you think you could torture before they all start blowing their brains out when threatened by capture? Getting some information out of thousands of prisoners is much better than getting everything out of several, no matter how important they are. And that is supposing that torture will work.
As a funny coincidence I was today rereading the second part of Marshall Vasily Ivanovich Chuikov's memoirs (????? ???????? ?????, "The End of 3rd Reich"). Chuikov was the guy who led the defence of Stalingrad proper and who later led the 8th Guards Breaktrough Army that, well, broke trough the German defence lines on at least three occasions while suffering few casualties (that is, "few" by Soviet standards, YMMV).
In the book he mentions what he found to be the most effective interrogation technique. Was it beatings? Sleep deprivation? Threatening to send them to Siberia for the rest of their wretched lives? [On occasion Soviets used all of those.]
No. The marshal found that the best way to make a POW talk was to give him a cigarette.
Does this mean that every captured German spilled his guts because he got a cigarette? Of course not. There was a great number of men who didn't tell anything. But kind treatment made enough Germans talk.