Salt by Adam Roberts
Intense, disturbing and prophetic. The fourth Roberts I've read, his first novel, and my second favorite after Gradisil. Ambitious themes, and complex implementation of them. The setup is the relativistic travel to and colonization of an alien planet, the titular Salt with all the material difficulties attendant on that. The main story is two first person narratives of people from two city states of differing ideologies and daily norms. The two communities have built up tensions, and eventually all out war.
One of most interesting things about this is the political parallel. There's a prosperous and plutocratic regime that undergoes a war in the desert to subdue another society, using the justification of faith as well as a recent and galling terrorist attack. It begins its reprisal with a major bombing to break the spirit of the populace, then moves in at force. Overt opposition is easily crushed and victory seems secured after a short time, but then it turns into a long occupation, attritional guerrilla warfare, and a slow disillusionment that causes political unrest. The invading country specifically paints all resistance against it as terrorism, insists such fighters are not legitimate soldiers and reserves the right to counteract such resistance through extraordinary and extrajudicial means. The reason I find this parallel good rather then eye-rolling is because Salt was written in 2000. Roberts had no way of knowing how much his scenario would resemble the reality of 9/11, the Afghanistan War, the Iraq War. Here I'd say is a good example of SF's ability to be thematically predictive, and have a continued relevance to understanding the way we operate now and the way we might in the future.
In any case, the larger power of the story comes from the way that both main characters, both narratives and both societies are flawed. Things seem at first to be rather balanced in one side, but they each have a lot of problems and injustices that they wear as badges of pride, and in particular there's one rather monstrous action by the 'more sympathetic' character that in retrospect was well set up and that lends a measure of uncertainty to trusting everything about his perspective. Seeing the logic and rationalizations of both sides as they fight and project the worst into their enemy makes for a complex as well as dramatic situation. On a direct plot level the book has no real conclusion, but it says everything Roberts needed to say about the outlined terms of his work.
If taken purely as a sort of dual dystopia, the book would be of limited value. In the end it's not that unique or compelling to demonstrate than authoritarian nationalism and conformist anarchy. I'd say the book works beyond that in the way it plays with the form of narrative. In a dystopian novel, there's almost always a level of trust with the story and the viewpoint of the individual existing in opposition to the dysfunctional system. This perspective might come to a point of defiance fairly early on, as occurs in 1984, or it might be near the end, see Kallocain and We, but the sense of opposition exists, and we're encouraged to trust the viewpoint of the individual and distrust the larger society. In Salt, we're encouraged to see faults in the authoritarian and anarchist societies, as linked to and enabling the untrustworthiness of both narratives. Like with Stone the individual is not enough, and here we're given a more direct way that the personal narratives of two individuals becomes linked to the wider social environment. Furthermore the two polities aren't in the stark dichotomy that it first appears--the apparently over-intrusive dictatorship Senaar features a callous abandonment and non-regulation of the poor underclass, while the free Alys ultimately depends on violence and coercion to maintain its effectiveness. This aspect is something neither of the two perspectives come close to perceiving, every element of their stories reinforces the level of separation and mutually exclusive character for the two polities.
Another strong element from Salt is the titular environment, and just how stark, materially austere and demanding the planet surface is. That gives a degree of solidity to the account and its drawn out story of personality justification and political conflict, as well as building on one of the more memorable speculative fiction environments. For all the playing with perspective and political models, in the end this book is vivid and engaging at least as much as it's interesting.
Better than: Stone by Adam Roberts
Worse than: The Dispossessed by Ursula K. Le Guin