The biggest geopolitical risk of our times is not a conflict between Israel and Iran over nuclear proliferation. Nor is it the risk of chronic disorder in an arc of instability that now runs from the Maghreb all the way to the Hindu Kush. It is not even the risk of Cold War II between Russia and the West over Ukraine. All of these are serious risks, of course; but none is as serious as the challenge of sustaining the peaceful character of China’s rise. That is why it is particularly disturbing to hear Japanese and Chinese officials and analysts compare the countries’ bilateral relationship to that between Britain and Germany on the eve of World War I.