"The Children of Men" by P.D. James (1992) is a good book. It is not very good nor is it medium. It is good.
The "Children of Men" is a movie directed by Alfonso Cuarón (2006) inspired by the just mentioned book. As a movie, it is neither very good or medium, it is good. There are plenty of alternatives to this movie but seeing it is not a waste of time.
Now, there is not much in common between the book and the movie. Character names are the same but not the characters themselves. Actually, I wonder why they used the same names for essentially different characters.
The basic story is the same, its background is more or less the same.
The book has a political appeal but it is not that political; it is more "human" (feelings, instincts and affections are of course also part of politics). P.D. James would probably not like to accept this, but as the book reaches its end, it communicates more and more directly to our instinct the fact that it was written by... a woman. (A man could of course describe this and that, it is not the descriptions themselves, it is the underlying "how to"). The book, eventhough absolutely bookish, has a deliberate vocation for a movie script.
The film is an action, political and war movie. Not much "human". Indeed, not much well defined. Interesting that the suffering and miserable illegal immigrants in England are German (and also French). Interesting that the English authorities behave as German authorities did during the 3rd Reich. There is even a ghetto. Contrarily to the book, all important cities of the world, including our city, fell into anarchy and or destruction. London was the exception. Is this also interesting? The movie could go without this assumptions. Yes, they seem assumptions to me; whose assumptions are these?