I faced the same problem two years ago, when I finished my first manuscript (I ended up trashing it). I remember it helped me a lot to just go back and reread everything I've written so far, and then form a general plot of it. Clear your mind, imagine you've done nothing to the story except develop an idea and perhaps the prologue, and twist it in random ways to see how it might end.
If nothing seems to work, maybe you're ending the story wrong. Maybe instead of ending it after the boy dies, end it the moment he breathes his last breath and leave the audience hanging. Cliffhangers are great.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.