The reputation of the “Iron chancellor” Otto von Bismarck (1815-1898) was established by his remarkable achievement in unifying Germany through three short victorious wars, from 1864-1870, that completely remade the European balance of power, and then orchestrating a generation of peace through a series of complex treaties that placed his country in amicable relations with all the continent’s great powers, except the irreconcilable French who were kept in a permanent state of diplomatic isolation. However, in 1890, Germany’s blundering new sovereign, Kaiser Wilhelm II, dismissed Bismarck from office and subsequently rejected the renewal of the Russo-German Treaty of Accord, which...