Is this a good book idea?

There is a young man of the age of 18 who was forced into fighting a war at the age of 15 because his father was a soldier who died and they need someone to take his place due to lack of troops. (This is where the book actually starts). Unfortunately he is on the losing side of the battle, and everyone knows it, so they send a kamikaze group in to try and sway the war. The main character volunteers and runs in preparing to die. Luckily, or unluckily however you look at it, he doesn't, but goes into comatose state where he rests for 30 years (in which time it recaps his time fighting). When he wakes up they don’t tell him anything, they keep him exiled only giving him enough sustenance to make it through the day (barely). Only letting him see light when they shine a flashlight in to check if he's still there. It's driving him crazy, he thinks it's worse than being in a coma. He needs to get out so he trains himself, but when the time comes the allure of the reason he's been kept captive is to strong that he decides to stay if only for a short time. When he finally finds out that it's been to stop the war and if he escapes they will destroy everyone he knows, hes got a choice to make.