why would they have to do this.

They wouldn't, because they forced unconditional surrender quickly.

where is stalin pulling thousands of landing craft

Off the shores of the East Asian Coast, where the Japanese left them when they surrendered.

Our of the docks of the Russian Pacific Fleet.

how many times can i reiterate this crucial point to you?

You can say the same words as many times as you like.

You're still not going to justify politically expedient genocide.