In this story Pratchett comments on the jingoistic nature of people, and man's desire to attack others for perceived ills to mask his own.  The book deals with a war between Ankh-Morpork and Klatch over the island of Leshp, which unexpectedly rises from the sea after centuries of submersion. When Samuel Vimes (who regards war as just a really big crime that everyone is afraid to make a law against) uncovers signs of a conspiracy, he and the members of the City Watch, with the assistance of the mysterious 71-Hour Ahmed, try to bring a stop to the oncoming conflict. Meanwhile, Fred Colon and Nobby Nobbs find themselves drafted by The Patrician and Leonard of Quirm into using an experimental Going-Under-the-Water-Safely Device to travel to Klatch and do some reconnaissance.  The story appears to have been loosely based on the real-life island of Ferdinandea.

An interesting story, there's many references to the first world war, as well as the first gulf war. The basic thrust of the story is the sudden and unnecesserily patriotism arising in Ankh-Morpork (mainly presented via Vimes' butler Willikins) after a new island is discovered, as both Ankh and Klatch want it. Klatch is once again presented as a rather Disc-alised version of The Arabian Nights. The Watch are caught up in all of this and Vimes goes off in pursuit of a suspect for a crime against the visiting Klatchian dignitaries. It all pretends to be really complicated but in the end it's very simple and Vimes ends up a Duke and Nobby looks for a potential girlfriend.