The 'Battle Hymn of the Tiger Mother' author is also a foreign policy expert, and her latest book delves into the impact ethnic and cultural rivalries can have on international relations - and how Americas blindness to this has led to domestic turmoil and foreign policy blunders.

New York Times journalist Emily Steel tells the inside story of the Bill O'Reilly investigation, and how she and her team persuaded a source to go public with allegations of sexual harassment.