It's not the easiest of comparisons to write, but it is not the most difficult. In my estimation, the impacts of war is where I think that the greatest comparison can be seen in both the book and the film. Essentially, you would be assessing how both depict the horrors of war and how this impacts both sets of characters. In Boyden's book, there is a desire to reclaim out of hope and redemption those who have to face the horrors of war. Elijah's war experience hollows him, making him almost unreachable upon his return. In the film, James' maverick and cavalier attitude is what distinguishes him on the battlefield, but also make him nearly unreachable at home. He cannot make the transition between deactivating roadside bombs in Iraq and grocery shopping at home. James has to end up going back to "what he loves," and this is where he has to be seen as incapable of redemption. I think that comparing and contrasting how the war impacts soldiers and their loved ones could be a good starting point on examining the dehumanizing effects of conflict, as well as the basic premise of how soldiers adjust and deal with their lives both in war and outside of it.