 shouldn't even be taking place. I mean, the alliance has to evolve. The world has changed. There are new threats, and the U.S. has huge responsibilities. The U.S. wants to remain, for the most part, many people, a predominant power on Earth. If it's going to do that, it has to have a strong economy, and there are some guns versus butter tradeoffs. Pepperdine University International Relations and Politics Professor Karan Skinner.