This has always been my take. If Russia were to destroy the us with all its nukes that assumes a few things:

Scenario A 1-that they are able to fire off nukes without any detection from the US without time to respond meaning they destroy the US completely 2- then what? Then the embargoes and sanctions are technically removed, but completely worthless. Russia cannot make any money or gain an additional power. That doesn’t guarantee subordination from all remaining powers. It more likely guarantees that nukes will already be in the air from other countries assuming they’re next.

Scenario B 1-Russia fires nukes, US catches them in time only to be able to respond with nukes ensuring mutual destruction 2-nothing is left, no one is able to make money or gain power when everyone is dead