That is the big issue with Stalin's plan. The USSR has between 120-150 nukes (the end of the year totals for 1953 and 1954), and furthermore lacks the capabilities to bomb much of the US (the Tupolev TU-4 is basically the only long-range bomber, and that couldn't reach the US). Meanwhile the US has between 1400-2100 nukes, and can use their bases in Europe to hit many Soviet cities. The Soviets' only hope is that Stalin backs down, and even then it might be too late.Wow, China will be hit badly...with this kind of attack a collapse of the front is on the table.
The problem are the consequence, the URSS will be forced to retaliate in some manner otherwise she will look weak...but on the other hand, an attack on western europe can spiral in WWIII and the Soviet lack the delivery system and the number of weapon to compete with america.
It will be interesting that if Operation North Star will happen...well at the same time there is a place in Viet nam where the use of Atomic weapons was proposed so even Operation Vulture can be approved as a mean to put pressure on the chinese