I did say it wasn’t comprehensive. That said, I am glad you brought that up because after I posted that I remembered from back in 1978 while attending Infantry School at Fort Benning, we had a day spent learning how to attack Soviet Army trench systems on a mockup.
Sorry, Calvin but way before this strip was drawn sitcoms mined that very same theme. It’s why the late Bob Newhart never wanted his character of Dr Bob Hartley to ever have kids with his wife played by Suzanne Pleshette. In an interview he said, “I told the creators I didn’t want any children, because I didn’t want it to be a show about ‘How stupid Daddy is, but we love him so much, let’s get him out of the trouble he’s gotten himself into’.”
Nope, sorry. Trench Warfare was seen in the Spanish Civil War, The Mannerheim Line during the Winter War in Finland, The Maginot Line in WW2 and the US & Chinese in the Korean War from 1951 to the end. Saddam Hussein famously tried trench warfare in the 1991 Gulf War and the US responded by burying the enemy soldiers by bulldozing their trenches on top of them. And that wasn’t even a comprehensive list.
I like the way I said it better.