Turtles Can Fly.
I don't really know whether to describe the plot here. It's not like it's difficult to find it online, it's just that it doesn't really do the film justice. It's bleak, harrowing and yet infinitely compelling. Despite not a single shot being fired in anger, it shows better than any other film I've seen the absolute, unrelenting and indiscriminate brutality of war and it's victimization of innocence and the innocent. It isn't a lavish film with a complex story, it just grinds out the simple lives of a band of children who neither deserve their fate nor have any real prospect of escape. Perhaps most hard hitting is that it's not difficult to know that every aspect, indignity and injustice of the story will have really happened at some point.
I realise that doesn't really sell the film a great deal. However, it is one that I can strongly recommend watching at least once. It's also quite honest and beautiful in it's telling and doesn't fall into dwelling and self-pitying. And of course, as with all stories like these, they deserve telling over and again until everyone gets the point.