It is worth mentioning what Adolf Hitler himself said about the development of a German nuclear bomb.

In his book “Meine Kommandounternehmen” (My Commando Missions, Limes, 1993, p. 149) SS General Otto Skorzeny wrote about a conversation he had with Hitler about this subject.

Can Germany Develop Nuclear Weapons? Skorzeny had heard a lot of rumors about Germany developing a nuclear bomb. As the commander of the SS- Jagdverbaende (commandos) he had heard of the work that has been done by German scientist at this time. In October 1944 he was involved in the preparations of the “Ardennenoffensive”, the so-called Operation “Greif”. To get the last orders he met Hitler in his headquarters in Eastern Prussia and used this opportunity to ask the Fuehrer about the ongoing rumors regarding the development of a nuclear weapon:

“Hitler looked at me with shining, feverish eyes:

“You know… Mr. Skorzeny, that if the energy won through nuclear fission and the radiation would be used as a weapon, that this would mean the end of our planet? The results would be horrible… Of course! Even if we could control the radiation and would use the nuclear fission as weapon, even then the results would be terrible! When Dr. Todt was here, I read that such a device with controlled radiation would set free an energy that would lead to a devastation only compared to what happened when meteors fell on Arizona and the Baikal lake.

That means that every kind of life, not only human, but also animal life and plants would be completely destroyed for hundreds of years in a radius of 40 kilometers. This would be the Apocalypse! And how should we keep the secret? Impossible! No! No country, no group of civilized persons could consciously take the responsibility. From strike to counter strike mankind would extinct itself. Only some tribes in the Amazon region and in the jungles of Sumatra would have a certain chance of survival.”

Hitler’s remarks continued for several more minutes. But I can recall them very well…”

What if Germany had somehow completed its nuclear weapons program in 1943?

The bomb(s) in question would be used primarily against Soviet troop concentrations. By removing massive numbers of men and materiel from the field, the outcome of the Russian front could differ significantly.

Delivery method is probably relatively low tech, using a truck or tractor to place a device as close to a staging area as possible.

If it were to be used against a city, Leningrad being wiped from the map might be it given the protracted siege from 1941-44. Stalingrad and Moscow were out of reach for most of 1943, and Kiev and Minsk were still in German hands. Still, the main goal will be in anything that will win the war, and creating a ruin that the Germans might have to rebuild once conquered is not ideal.