I'm not sure what you are saying. I'm not saying you won't have disorganized, nor “terror” attacks. Anything which has “plausible deniability” will probably be respected. The issue is not about "honor", it is about ownership of the government.
I'm saying that organized, hierarchical countries have CENTRALIZED institutions which are very vulnerable. And vulnerable kleptocrats who decide they, personally, have nothing to lose can be expected to say "F it!" and take the whole world with them.
And all that is my THEORY -- which holds up through all of the nuclear weapons age to date. Even governments who don't care about their citizens care about their centralized power...and THEMSELVES. And centralized government power goes into the crapper pretty much with the very first nuclear strike.
All bets are off once the attack is direct enough and can be directly assigned to a power on the other side.
But now the rule is being "bent". Because the US PRETENDS it is not engaging in a kinetic war with Russia. And, so far, Russia's hierarchy is PRETENDING they are not at war with the US -- only "sanctioned". And, so far, Russia's hierarchy does not feel they, and their power, is personally theatened.
Once someone slips in this PRETEND game, or someone with enough power or enough to lose feels they are going to lose (or feels they have nothing to personally lose any more) the endgame can escalate to unstoppable in minutes. And unstoppable stops with nuclear. And then nuclear MAD.
Mutually Assured Destruction has held things together since 1950 by forestalling kinetic war between enemies. USSR didn't escalate to nuclear exchange with the US, mostly because the US deliberately didn't poke the bear; the USSR failed internally, and not as a result of a direct war with the US. Indeed, the situation in USSR must have been evident to anyone over there with half a brain: the USSR was based on a bad ideas of Marx (not even a Russian).
But Ukraine breaks that "gentleman's agreement", it crosses the old lines of MAD deterrence. The US is making it VERY undeniable that our Regime is at war with Russia. Not with Putin, personally, even: with Russia. We are in uncharted territory now.
Imagine if Hitler were still alive, in his bunker beneath Berlin, but THIS time he had thousands of nuclear warheads. AND THE MEANS TO DELIVER. Do you really think he wouldn't have been willing to take the whole world with him, before he shot his wife, and then himself?
Only in this case, the bunkers with the MAD Men are in Washington D.C. and -- arguably -- Russia. "Better DEAD than Red!" Yeah, sure. Try explaining that to the grandchildren.