Dear Gideon and Bob,
Thanks for your response, Gideon!
To move the ball into Bob's court, a few queries. In his response, Gideon suggests your data on the persistence of American power are somewhat off. He's not the only one; Robert Pape made points like this a few years ago in the National Interest, and Edward Luce has made similar points this week in the Financial Times. Without going too far down the rabbit hole of data, alternative data series can probably be arranged that show a more secular U.S. decline since the 1960s. How crucial is this data question to your overall argument? More generally, what about going forward? Gideon's point about China is well-taken; even if it does suffer a growth slowdown, would that necessarily slow down its eventual rise? The United States suffered some serious depressions during the late 19th century and still became the world's leading industrial power.
Gideon's response highlights another brewing problem with American primacy: Even if the United States is not declining, its long-standing allies are in serious trouble. America's NATO allies are entangled in a sovereign debt crisis, and Japan has its own demographic issues. There are other allies, but as Gideon notes, they have become highly interdependent with China. There are rising states that might share American values -- Brazil and India, for instance -- but it's far from clear whether their alignments with the United States will be anything more than tactical. Without supporters, can the United States still lead?
Finally, we know Obama has read the New Republic excerpt of your book. Has Mitt Romney? I'm curious because a) you're a foreign-policy advisor for him, and b) the Republican presidential candidate's rhetoric on this point -- that Obama believes in American decline, while he believes this will be an American century -- seems at odds with Obama's embrace of your argument.
Dear Dan and Gideon,
Many thanks to you both for this lively and important discussion. I'm glad Obama mentioned the excerpt from my book, not only for the obvious reasons, but also because he has kicked off a genuinely useful debate about the relative position of the United States and other powers in the international system. We seem to have slipped into a "post-American world" a couple of years ago without much rigorous analysis of whether that was really a good description of the international system. I believe it is not.
First, those GDP figures. My argument that the U.S. share has held fairly steady with roughly a quarter of world GDP since 1969 rests on the U.S. government's figures, which can be found here.
Anyone who takes the trouble to look into this question quickly discovers that, of course, the numbers are a bit all over the place. The IMF's own numbers are constantly changing, even in regard to the past. For instance, as I wrote in response to Luce and Sachs, according to the IMF's 2010 World Economic Outlook report, the U.S. share of world GDP based on purchasing power parity in 1980 was 22.499 percent. In 2007, the last year before the Great Recession, the U.S. share was 21.289 -- not much of a shift. In its 2011 report, however, the IMF put the share in 1980 at 24.6, making the shift seem greater. Which is right? As for the IMF's projections, can we wait and see how they turn out before building an entire global theory around them? They are constantly revising those up and down, too, and things may look different when the United States pulls out of its recession.
But how much weight should we put on this statistic in any case? Some, surely. There is no question that as China's share of the global economy grows, Chinese influence will grow in some respects as well. But I find it remarkable that in so many of these discussions, those who point to China's growing GDP share neglect to mention that China's per capita GDP is a fraction of that of the United States and other leading economic powers. Per capita GDP in the United States is over $40,000; in China it is a little over $4,000, roughly the same level as in Angola and Belize. Even if optimistic forecasts are correct, by 2030 China's per capita GDP will still be only half that of the United States, roughly where Slovenia's is today. It is interesting to contemplate what this might mean if China were to become economically dominant, because it is historically unprecedented; in the past, the world's dominant powers have also been the world's richest.