I would like to suggest a small tweak, perhaps instead of nuking the entire world, the offended parties could merely nuke the protagonists home country? Or perhaps they wouldn't resort to nuking at all. You could see a scale depending on their reaction. So while knocking a wineglass over would absolutely incense everyone, they might be a little more restrained if you've buttered them off ahead of time.
So depending on how they feel at the end of the night or when you get tossed out of the party you'd get different possible dialogues:
5: "Splendid old chap! Come by the manor tomorrow for your knighthood and your country's new humanitarian aid package!"
4: "Do you have a son or daughter that I can give a ridiculously well paid job to?"
3: "I say, I say, I hope to see you again soon. Stop by the embassy sometime."
2: "It was a lovely night, thank you for coming."
1: "Well you handled yourself well enough."
0: "Terribly sorry, were you supposed to be here?"
-1: "I can't believe they let an buffoon like you in here."
-2: "Tell the oafs your country calls athletes not to bother coming to the next Olympics."
-3: "If you leave the house immediately, I'll give you sixty seconds before I release the hounds."
-4: "What an impudent peasant! Off with his head! Sanction his country! Call Madagascar and shut down everything!"
-5: "I say, I say, where did I put that red button?"
Your relationship with each dignitary would start off at 0 and would go down by 5 if you make a faux pass. If your relationship is ever negative, it's immediate game over. But if you make it to the end of the night with a positive relationship, you get a score boost. So walk right in the door and spill wine on someone and it's curtains for your country. Lacy, gently wafting curtains. But if you manage to keep from embarrassing yourself quite so quickly it's not so severe.