A Long Way Gone: Memoirs of a Boy Soldier by Ishmael Beah. Former child soldier Beah recounts his experience fighting in Sierra Leone. This is a tragic form of human trafficking that takes advantage of orphaned youth and forces them to commit the unspeakable.
If you had told me that I would love a book written entirely in letter form, I would have laughed. But this story about the WW2 Channel Islands and their inhabitants' suffering and triumphs is one of the best stories I have ever read.