Under the rule of Recep Tayyip Erdogan Turkey has descended into a dictatorship, promotes the Islamist agenda, abuses human rights, limits freedom of expression in the press, and wages war against the Kurds. While Turkey has historically been important geopolitically, it has become an outlier in Europe and an uncertain ally of the United States.

An Uncertain Ally is a straightforward indictment of Erdogan. Drawing on inside sources in his Justice and Development Party (AKP) and the police, the book reveals corruption and money laundering schemes that benefitted Erdogan, his...