First of all, Monstrous Regiment is the 28th Discworld book, and Pratchett is just getting started. Every time you think he has run out of ideas, he comes up with something new (or an interesting take on something old). This book is no different, as this time he examines the military and the military mindset. Is it a good one? SIR, YES SIR!
This is another winning Discworld book. It's a bit different in tone from Night Watch, if only because the humour is broader. In Night Watch, the humour was on the side and it was a fairly serious book except for that. This has a serious point to make as well, but the humour involves everybody. It was refreshing to see. Pratchett has some good points to make on military matters in the real world, and he skewers the entire mindset (not necessarily of the men, who he never really disparages, but the planners).
He does have the obvious stereotypes of the hard drill sergeant and the lieutenant who doesn't really know what he's doing and has no experience. But even these stereotypes he turns on their heads, shakes them upside down, and looks at what comes out. Pratchett, always a master of character, has created some new winners (though I don't believe they'll be back in another book, like some of Pratchett's recurring characters). Polly is the typical Pratchett hero: determined, relatively straight-laced, intelligent and resourceful. She's a wonderful viewpoint character, scared but determined to do what is right. When she's assigned to be the lieutenant's assistant, she's reluctant to take advantage of the position, though she does so to help out her mates. She helps Lieutenant Blouse along, though she's terrified of shaving him because she's never learned how to shave herself.
Probably the best character in the book, though, is Jackrum. He reminds me a lot of Sam Vimes from the City Watch books, but with a different edge to him. He's a soldier and nothing else. He doesn't want to be an officer. He doesn't want to be a civilian. He wants to do his job, keep his lads safe, and bring them home. He doesn't like sneaking around and doing things different from the army way, and he's horrified when Blouse wants to use subterfuge to get into the castle they're supposed to take. He's a man of duty, honour, and integrity, and while he's always rough on his men, he also respects them. Of course, we find out there's a reason behind the man he is, which is what really cuts him apart from Vimes.
The other characters are standout even if they aren't developed that much. There's the religious zealot who constantly speaks to "The Duchess," (the figure who, much like Queen Victoria, hasn't been seen much since her husband died, and who many feel is actually dead). There are a couple of fire-bugs who ran away from where they were being held. The best of this bunch, however, is the vampire (Maladict) and the latest in a long string of Igors in a Discworld book. Maladict has sworn off blood in order to be accepted in society, and has developed an addiction to coffee instead. He's the only one that seems, at least initially, to know what's going on. When the coffee runs out, look out! Igor is much the same as most of his brethren, handy with a surgical knife and internal organs. Both of these characters add some sparkle when they're on the page, as well as a lot of laughs.
There are a few well-known Discworld characters in the book to add colour as well. William de Worde (the journalist from The Truth) and his photographer vampire Otto, make an appearance. I'm surprised that they weren't "embedded" with the troops, but that may have been a bit obvious. Pratchett does use them to make some statements about the Press in wartime, and how wars are reported. Samuel Vimes and a couple of his watchmen are also included, though they don't have a major part. I think Vimes is included mainly as a counterpoint for Jackrum's character, and he does a good job of that. He's also a voice of reason in a sea of insanity (Polly's adrift in that sea, so she doesn't count).
The best thing about Pratchett is that he is entertaining and thought-provoking even when you might not agree with him. Given some of the things he makes light of, I may be able to guess what his opinion is on the recent war in Iraq. However, even if you don't agree with him, he will make you think. And he will make you laugh, which is the most important part. He also touches on gender and religious issues, all in one book. The fact that he's able to make interesting points without seeming like a scattershot approach says something about Pratchett's writing.
Monstrous Regiment is a return of sorts to Pratchett's previous style of combining humour and social commentary. It's another must-read for any Pratchett fan.