Since then....the Little Tigers and China, and things are getting better in India. The EU may be the next superpower.
Leary, cheerful soul that he was, didn't discuss what happens in countries the center of wealth is moving away from--do they necessarily do gratuitously stupid things instead of declining gracefully? Or do people always do gratuitously stupid things, but the effects are more visible when you aren't lucky?
Leary didn't offer a plausible mechanism for the center of wealth going west, and I can't imagine what such an explanation would look like.
The good news (if there's anything at all to the theory) is that the center doesn't just go west, it's accelerating. The acceleration was part of the theory in the 70s, and it's still part of the pattern. Things may well improve dramatically (though maybe only for a couple of years) here on the East Coast of the US in a decade or so. Eventually, the center of wealth will be zorching along around the planet so fast that people will make their investments exactly timed to accomodate it.