Use Of Weapons by Iain M. Banks.

I am slowly going through Bank's Culture novels.

Some thoughts on the Culture series. There doesn't appear to be an overall narrative arc. He uses "The Culture" as a background to tell whatever type of science fiction he wants. He doesn't have to recreate the universe when a new idea hits him. The Culture is big enough that many sci-fi ideas can fit into it.

Use of Weapons follows a man who the Culture has hired to intervene in wars of non-Culture societies to help them end with less bloodshed. Or maybe that's end to the Culture's advantage. Zakalwei (The protagonist) can never really tell.

There is much in this book as it alternates between the main-story, and the background story of Zakalwei. There is a lot of powerful and exciting writing in this novel. But the shifts in location and story line are very abrupt.  I'm also not a big fan of the final "Twist" With a good twist, you can go back and go over the clues that you missed. No so much here. The twist felt bolted on, like something that occurred to Banks at the last minute. Not something that was woven into the story from the beginning.