The bipolar theorists like Kenneth Waltz were a bit freaked out at the Soviet collapse because their schema was “two big powers = stable world” and suddenly the world looked unipolar and dangerous. So along came the power transition people who said “one big power = stable world” and that idea has a lot of appeal. (People find comfort in theories that support the status quo, of course.) What’s more, the power transition people looked back and said, “Yeah, the US was the hegemon back then, too, and the Soviets were never really close.” This kind of revision required changing the definition of hegemony somewhat, especially in terms of including “soft power,” which the US had in abundance for decades.

So, how does the East-West divide during the Cold War fit into America’s hegemon title? I’m guessing on a global influence level, the former USSR was a lot closer to challenging the US than China is now, no?

As for the length of American hegemony, I was paraphrasing Ikenberry and the words I used were “so long,” as opposed to short-lived. Militarily speaking, the US was a regional hegemon in the Western hemisphere starting in the 1820s, and by the early 1900s had replaced Britain as the economic center of the world. And then, starting in the early 40s, the US emerged as a military hegemon as well, and it used this combination of military and economic power to craft the institutions Ikenberry lauds. So we can say the US has been the total systemic hegemon for about 60 years, but before that it was a cultural and economic hegemon starting around WWI.

Moving on, it should be noted that power transition theory generally looks at the last 500 years of history, when empires first became truly global thanks to sea power and when economies became dynamic thanks to capitalism. In terms of the theory, 60 years is a good run, and no country has remained hegemon much more than 90 years. We may think of British hegemony as lasting roughly 200 years because Britain first defeated the Dutch at the end of the 17th century to become hegemon, then defeated its main challenger the French to become hegemon again at the start of the 19th century until the Germans rocked the boat at the start of the 20th century. Political scientists usually break these two periods apart owing to the fact that there was a real perception that Napoleonic France was going to become the new hegemon — just look at Napoleon’s Qin Shihuang-esque reforms in Europe, which seem the work of a hegemonic power.

(Sorry to get into this so much; it was one of my favorite theories to discuss in grad school.)

Finally, I can’t close this topic without noting that a sentence Ikenberry wrote in the middle of his essay struck a nerve with me. “War-driven change has been abolished as a historical process.” That is a ridiculously absolute statement for a scholar to make, though at the same time I hope to God we don’t see Ikenberry proven wrong.

That sums it up for me. “Change” is exactly the banner that the US tends to fly while initiating war. You’re right that it is an ridiculously absolute statement for (anyone) to make, and I agree in that I wish it could be true. But it’s proven wrong everyday.

One other thing I’m not so certain about is where you use “long” to describe the US hegemony. Not much over half a century isn’t, historically, that long of a hegemony, is it?