[Mirioron]

One of the scenarios I keep thinking about is what if either side uses just one nuke. They let the other side know that they're going to use just one and do it. Do you respond to that with your full arsenal? Do you go tit-for-tat? Do you just let them get away with it?

[lumost]

This was a common war game scenario in the Cold War. NATO semi-intentionally adopted the strategy that they would have enough troops in western Europe to fight an invasion, but that they would need tactical nukes to block the invasion. NATO war games were then focused on how the conflict escalates, with the general conclusion that both sides would engage in tit for tat strikes until some threshold was triggered and a full nuclear war broke out (Use it or lose it scenario).

A close example to your scenario was South Africa's nuclear arsenal as well as (potentially) Israel's. The game theory somewhat works out if the belligerent party only has a few nukes and would be unable to escalate to full nuclear war due to lack of weapons. It's considered a dangerous and unstable scenario as such parties could actually use nukes without fear of MAD.

https://en.wikipedia.org/wiki/South_Africa_and_weapons_of_ma...

https://en.wikipedia.org/wiki/Vela_incident

https://en.wikipedia.org/wiki/Deterrence_theory#Coercive_cre...

[Mirioron]

Is this why the US has focused so much on the ability to shoot down ICBMs? Because if they can shoot down even just a few tit-for-tat doesn't really work against them anymore.

[jacquesm]

No, that just pushes the opponent to throw all of their stuff at you.

[tedunangst]

This is why you have a preprogrammed unstoppable retaliatory doomsday counter weapon. Just remember to inform the other side about it before first strike.

[jacquesm]

In case someone doesn't get it:

https://en.wikipedia.org/wiki/Dr._Strangelove

[tacon]

Echoes of the plot of Fail Safe[0]

[0] https://en.wikipedia.org/wiki/Fail_Safe_(1964_film)