The common answer to that question is that history is written by the winners, but that's not completely accurate. Sure, if there's a war, and one side annihilates the other, most likely it will be the survivors—or, we suppose, the "winners"—who will be creating the outline for the history book. But when there are survivors on both sides, as there usually are, the details of an event may be remembered, and eventually recorded, from more than one perspective.
All Quiet on the Western Front, though fiction, offers a narrative of World War I from a perspective many of your students will not have fully considered before: that of the enemy. And in this book, it turns out that the enemy has an awful lot in common with the ally.