There is a small but significant industry in the United States that predicts a "coming war" with China, and Atlantic Magazine is foremost among reputable American monthlies in giving a home to such speculation. It has just done it again, in an article that includes a hearty dose of geopolitical theory. The theory is the "Thucydides Trap."

The author is Graham Allison of Harvard University, the man who coined that phrase. Thucydides, the historian of the Peloponnesian War in the 5th century BC, explained what caused the war this way: "It was the rise of Athens, and the fear that this inspired in Sparta, that made war inevitable." It lasted 20 years, and at the end of it the two great powers of the ancient Greek world were both devastated.

Yet they didn't really go to war over anything in particular, according to Thucydides. The problem was that Athens was overtaking Sparta in power (like China is overtaking the U.S. now), and just that one fact was enough to send them to war. So are China and the U.S. doomed to go to war in the next decade?