Gotta get people reading more history textbooks and visiting more 20th-century museums. Some, like the Holocaust Museum in DC, are about as pleasant as getting a fishhook caught in your open eye. Which is some of the most compelling arguments for peace I've ever seen. The pictures are etched into my mind decades later, and I still remember the smell of all the leather shoes in there.
I'd like to visit France and Belgum and Italy soon to see the WW1 sites. We've done Normandy and WW2 across Europe and the Pacific. It's also incredibly somber arguments for peace.