The Lie by Helen Dunmore was published in 2014.
The setting is Cornwall 1920, but the story often slips back to the World War 1 experiences of Daniel and Frederick, and their childhood together. Frederick and his sister Felicia are the children of a man who had made money in Australian mines, as Daniel’s mother had been the cleaner for the family she had become close to their mother, when the mother died Daniel’s mother helped with bringing up the children. But Frederick and Felicia go to private schools, Frederick isn’t interested in learning. It’s Daniel who is the clever one, but he knows he’s never going to be able to stay on at the village school, or have the opportunities that Frederick will have. But they still manage to have a close frienship. When war breaks out they find themselves in the same unit, but of course Frederick is an officer and Daniel isn’t. Only one of them comes back from the war.
I’ve read quite a lot of books which feature WW1 but I think this one depicts the horror of it more than most, and the lack of gratitude and sympathy that those not involved at the front had for the survivors.
This is a great read if you are interested in that era as Helen Dunmore obviously was as she wrote a few books which feature WW1. She was a talented writer, what a sad loss her death was.