Douthat wades into the debate:
Manzi makes the sensible point that his essay (like my column, which quoted from it) was focusing on America’s position on the global stage as well as our domestic situation, and when it comes to global politics the sheer size of your economy — and not just your per capita wealth — matters a great deal.
On a per capita basis, after all, the richest countries in the world include Singapore, Qatar and Brunei, which nobody would confuse with great powers capable of playing a significant role in promoting stability, liberty and growth — or exerting significant cultural influence, for that matter — on the world stage. (Taiwan’s impressive per person G.D.P., Manzi points out, does not prevent it from being swallowed by mainland China; that job is the left to the U.S. Navy.)
Obviously, Western Europe is considerably more powerful and secure than Singapore and Taiwan. But just as obviously, Europe, too, is a beneficiary of the Pax Americana, and the outsize military spending that our overall economic size makes possible. And a world in which America’s economy had grown at European rates since the 1970s would be a very different place — less congenial to our own interests, and probably less stable and prosperous overall — even if our per capita G.D.P. had continued to rise smartly across that period.
The Dish 