[Alastor Mobius Toth]

It's not a huge assumption. USSR plans for WWIII included limited nuclear strikes across entire Europe. The political leadership of USSR did not even give a remote dammn about its own people, and given the situation, they are probably worse in Alt!Earth.
I mean, they were happy sacrificing most of European military forces to get their share of G-elements, and as result of their failure entire Europe got nommed. No, they do not deserve a vote of confidence. Nobody does, because all MuvLuv natiosn are equally bad or corrupted - U.S has AMERICA, USSR had COMMUNIST BULLSHIT, Japan has YAMATO DAMASHII...

Also, do note that there is a difference between strategically sabotaging Soviet war effort without completely eliminating it (which is what Infinities are doing) and the Red Shift plan.

The way I understand it, Red Shift is something completely different - it's the last proverbial "Holy Shit, everything is going down" plan meant to be issued in case of immediate overrun of Alaska by BETA. It's not that everyone expects Soviets to fail, but in case they do, you gotta have a back-up plan. Now, if only Americans didn't have to use Hydrogen bombs out of all things...and if you think about it, if BETAs invade Alaska, then it means Kamchatka was overrun, which would indicate that almost all Soviets are dead anyway.

Funny enough, Poland had a similar plan during WWII that involved blowing up a part of peninsula of Hel to make it an island to wither Nazi siege. Curiously, it failed because detonators didn't go off, from what I remember.

Also, take into consideration that Soviet officers are aware of it - Rogovsky/Rogofski being knows it (it's a good bet that Sandek is being left out of the loop, being Polish; or is just bullshiting to Yuuya, which is likely given he had Zhar battalion killed). And they don't seem to care. That should say volumes about their attitude to just about everything. Even potentially giving them any advantage is risky at best. U.S is being pragmatic, and probably every government in their position would do the same.

Saying that America is trying to get all Soviets to die in a blaze of thermonuclear glory is a bit of a stretch. If this was the case, they could have simply make USSR starve to death in Kamchatka, and stop supplying their military. Fulcrum? Terminator? Berkut, of all things - they are all made with U.S technology, and with covert assistance of U.S tech specialists.