War Horse author Michael Morpurgo, pictured right, says Britain has failed to learn many lessons from history.
The author and former Children's Laureate, 69, is about to see Private Peaceful, another of his novels set in First World War trenches, adapted for the big-screen.
He told the Radio Times: "To me, these soldiers in the First World War were sent off like cattle. In fact, the men were treated very much like the horses – which is one reason I think War Horse works so well."
The writer, who decided that he would get involved in film versions of his books after finding that he could not "make inroads" into the big-screen adaptation of War Horse, added: "It's always old men sending young men to war. I do feel we haven't learnt very much from history.
"Now we wrap Union Jacks round the coffins of the dead.
"What we still don't see, what we still don't really have in our faces, is what war does to bodies. They still don't tell you the number of wounded. Which is huge."