The trenches changed everything, swept away the notion of the individual glory of war, consumed an entire generation of French, Germans, and Brits. And nothing was learned. The Armistice was just a time out to breed up a new crop of cannon fodder for WWII.
The level of suffering in the Soviet Union during “The Great Patriotic War” may be unparalleled in the history of warfare, both for civilians and soldiers. It boggles my mind that any country could absorb such losses, hold, and then win. Your students need to know about their grandfathers and mothers.
Teaching about war is hard. I used to teach The Things They Carried. It wasn’t easy. But some of my students had fathers and uncles who served and told me it really helped them to understand. All any teacher can do is try.