Turkey is on a predictable and consistent trajectory, with two key dates as inflection points. In 1842, Abdülmecid I ordered the construction, on the edge of the Bosphorus, of Dolmabahçe Palace, the new seat of the sultanate.

Until then, the center of Ottoman power was in Topkapi, in the heart of a sweltering old city, swept away by plague epidemics. After conquering Constantinople in 1453, Mehmet II preferred...