[Snargorf]

If there ever was a major war between civilized nuclear powers, and it didn't immediately go nuclear, we might end up with a weird sort of gentleman's agreement where it's accepted to fire nukes into your own country (at invading enemy forces) but not at another country.

I can see that being an evolutionarily stable strategy.

[manachar]

I would think that a cold war situation is far more likely. No reason to use nukes in your own territory, many very good reasons to not use nukes at all. So long as the early warning systems (i.e. satellites) are still in place we will probably assume that the other side would rather avoid irradiating their own territory and prefer other aggressive tactics.

[ethbro]

My extremely boiled down version of the MAD calculus was that one was only required to use nuclear weapons if one's capability to use sufficient nuclear weapons at some future point in time were being lost.

Hence the Cuban missile crisis being such a big deal.

[gspetr]

> we might end up with a weird sort of gentleman's agreement where it's accepted to fire nukes into your own country (at invading enemy forces)

There was exactly this type of thing: https://en.wikipedia.org/wiki/Nuclear_artillery