One hundred years ago, America entered the First World War. It was sparked by one of history’s most notorious wrong turns. That single blunder ignited a conflict that would claim more than 37 million casualties and sow the seeds of geopolitical strife for generations to come. This week, the PBS program American Experience is airing a three-part examination of WWI. Podcast host Dan Carlin appears in the program, and he joins us Monday to discuss the war’s outbreak and its place in history.