No, Really. What is so Funny About Peace, Love & Understanding?

A little something for your weekend - a duet between Nick Lowe, who wrote this song, and the Elvis of import, who made it a classic. For extra credit, answer the question: what is so funny about peace, love, and understanding? And why is it that the people who argue for that are considered naive and simple and the people who argue for something as messy, dangerous, and unpredictable as war are considered pragmatic? When will neuroscientists find the switch for organized violence and simply switch it off? (What was it my son said the other day? "This isn't rocket surgery.") I'll shut up now and just let you enjoy the song while formulating your own follow up questions.