Two words: Manhattan Project. Unless you remove the A-bomb from the

scene,

Germany will get nuked instead of Japan if WW2 is still going on by

1946.

If the A-bomb could be delivered to Germany to begin with the war is
already over.

Walkers won't be of any help. With the attitude of the time, they would

have

been lobbing A-bombs all over Europe to stop those walkers if they had

to.

Um, no. A-bombs would be worthless as a real tactical asset of the time.
Remember that the US had exhausted their stockpile of two atomic weapons
by the time of Japan's surrender.

Baka. When Japan surrendered there was a third nuke on it's way over (it was
to be droped on Tokyo).

Psycho Sam