It's not so black or white. The International Criminal Court is one real-world example. The United States (to its shame, IMO) is not part of the ICC, yet most

It's not so black or white. The International Criminal Court is one real-world example. The United States (to its shame, IMO) is not part of the ICC, yet most countries are and the institution is valuable despite not having 100% buy-in around the globe. Also the Prisoner's Dilemma over multiple rounds teaches different lessons than when it's a one-off situation.