Slitherine

The nuclear missile text dialog states that its use will "Declare War on Affected Faction". However when I tried to attack another faction using the nuclear missile it was not allowed. My guess is that this was the case because I have a non-aggression pact in effect with that faction? if so then perhaps the text should read:

"Use will declare war on affected faction unless non-aggression pact is in effect"

Unrelated, but I have read that in the end game the other factions do not use the nuclear missile option. That has not been my experience, as in my current game I had a large attacking stack of my units hit by another factions nuclear missile. Perhaps this was a fix introduced after pervious beta comments. If so well done. Caught me by surprise.

I don't remember reading about inability of factions to use weapons in the end game, but I once complained that I couldn't use those weapons after the end of the game. I simply wanted to blow everything before leaving the map, but I had non-aggression pacts with everyone and diplomacy stopped working after the end of the game.

I think you should be able to end a non-aggression pact with a war declaration - but with diplomatic repercussion from all other factions. Like it hurts your credibility as a friend because you broke the agreement. Same thing if you end a non-aggression pact the normal way but you do something warlike to that faction within the 5 turns of truce. When I say diplomatic repercussion, I think it should dock you a level of "attitude" with each of the remaining factions...(or something more or less severe. The exact penalty would need a more thorough discussion). This would encourage people to break the pact properly and wait out the 5 turns of truce afterwards before attacking; but they'd still have the option to start a war immediately even though they lose friends in the process.

So if you want to attack or nuke someone with whom you have a non-aggression pact or had one recently (the truce time following pact), you should get a confirmation dialog saying that you have (or recently had) a pact - if you continue, all other factions will think less of you and will be less likely to sign non-aggression pacts with you in the future.