Consider Phlebas by Iain M. Banks

What happens when an immovable object meets an irresistible force?  You get a war between two galactic evenly-matched power-blocs that no one can win.  That is the basic theme of this novel by Iain M. Banks.

On the one hand we have The Culture, a society spanning a multitude of star-systems.  Their culture is non-expansionary and hedonistic.  Their social policy aims at producing the greatest good for the greatest number of people.  The Idirans, on the other hand, are an expansionist warrior race who aim at subjugating other species with the aim of furthering their religious cause.  Both sides are fighting to protect what each sees as its raison d'etre.

The plot follows the exploits of a mercenary called Bora Horza Gobuchul.  Horza is a genetically modified human chameleon who can alter his appearance to identically impersonate other humans.  He has been enlisted by the Idirans to capture a Culture Mind (a computer with an artificial intelligence of almost unimaginable ability) marooned on a politically neutral planet.  In the course of executing his mission, Horza is imprisoned and rescued, he murders and thieves, and causes mayhem and destruction.

Consider Phlebas is both worthy and unworthy.  Worthy because Banks examines the Machiavellian principle of the ends justifying the means - almost a trillion people die in a war that ends in stalemate.  Was it worth it?  And unworthy because, in essence, the action is little more than a series improbable escapes, gratuitous individual violence and some shoot-'em-up scenarios.  At over 400 pages, it all goes on more than a little too long.  Banks does provide us with some thought-provoking material, such as: what would it be like if the meal on your plate was sentient and could talk to you and protest as you ate it?  But in the end, such scenes occupy too little space in the overall scheme.  To paraphrase the Emperor in Amadeus: "Too many words. There it is."

Publishing details: Consider Phlebas by Iain M. Banks, Orbit Books, London, 2002, (originally published 1987) pp.467