In the decades that followed, the ISI has come to wield undisputed power across the region-in 1988 its involvement in Kashmir came under increasing scrutiny, and by 1995 its mentoring of what became the Afghan Taliban was well known. But it was the alleged links with al-Qaeda and the discovery of Osama bin Laden in Abbottabad, at the heart of Pakistan's military zone, that really put the spotlight on the ISI outside the subcontinent. Controversies have dogged every step of the organisation since its inception, right from its role in Pakistan's testing of a nuclear weapon in 1998 to its links with A.Q. Khan.

Hein G. Kiessling methodically peels back the layers to expose the shady world of Pakistan's secret service. In his many years in Pakistan, the author forged close contacts with several key players, which gave him fresh, often startling, insights into the ISI as a domestic and international actor. Faith, Unity, Discipline is a crucial addition to the literature on the workings of intelligence agencies, on Pakistan and, indeed, on South Asia and international politics.