After the Portuguese arrived in 1543, the xenophobic Japanese restricted foreigners to the city of Nagasaki. The Portuguese were eventually kicked out for meddling in politics and religion and were replaced by the Dutch; but they, too, were penned up in the city. For 300 years Western technology flowed in through this one port and the smartest people in Japan travelled there to encounter Europe’s finest. Nagasaki, says Harvard economist Edward Glaeser, was the foundation of Japan’s greatness.

Xenophobia turned this city into a hothouse of ideas. People met face to face and discussed the latest technology. The Japanese absorbed and improved Western innovations and became, in the twentieth century, a military and economic superpower, able to challenge and often beat the Americans at their own