Ah, I see, given these estimates, I can understand why this does not look like a Pascal's wager to you. It seems to me that the odds look so grave to you because you gloss over several steps during this potential escalation. For example, "Russians intervening militarily" could be anything from posturing to weapon shipments to a surgical strike to a Czechoslovakia-style tank-roll or Afghanistan invasion. My guess that the odds of the latter is below 5%, as it has not happened since (Chechnya was the closest case and that was a Russian territory actively hostile to Moscow). Similarly for every other case. Note that the scenario you describe (Soviets invading and losing) happened in a much more tense atmosphere in Afghanistan, and there isn't even a hint of the Soviet leaders at the time seriously considering nuclear escalation. So, the historical reference classes do not seem to bear out your estimates.