I am admittedly a history noob, so apologies if this has been covered or is easily looked up (or if the question stems from some sort of misunderstanding of events). Dan Carlin, in hardcore history episode 59, mentions that Stalin was such a problem in the era 1957-1952 that the US was strongly considering dropping atomic weapons on Communist Russia to thwart their advance. But why would it not be better to somehow assassinate him, or even drop some standard bombs? Was the bombing technology not advanced enough to target his living quarters specifically, or was there another reason? Were the US generals at the time even considering this?
Run through the consequences of this. What happens after you somehow kill Stalin? (Which would be difficult enough: the Soviet Union was a closed state, and the US had a very difficult time knowing what was going on in there, much less somehow knowing where Stalin was at any given time and somehow managing a successful operation against him.) What would the next Soviet leader's response be? (If you think it will be gratitude, you'd be very wrong.)
At a minimum would be inviting reciprocal assassination attempts. At a maximum you are talking about the spur for another world war.
This would not be an alternative to war — it would be war.