The Salvation War Web Original trilogy is based on this premise. And boy does it makes good use of it.
I've just been reading it.
“We have had some such troubles, yes. I suggest, Mister President, that you tell your people what I told mine. In view of the circumstances, Britannia waives the rules.”
Oh dear... this series looks to be fun and really really bad.
"Good Omens" (Pratchett and Gaiman) is an excellent book along such apocalyptic lines.
This is our monthly thread for collecting these little gems and pearls of wisdom, rationality-related quotes you've seen recently, or had stored in your quotesfile for ages, and which might be handy to link to in one of our discussions.