Reporter: President Obama's biggest challenges listen

Tags: Politics, foreign policy

David Sanger covers the White House for the New York Times, and is the author of the new book, The Inheritance: The World Obama Confronts and the Challenges to American Power.

Among the revelations in the book is that the U.S. has funded the Pakistani government to the tune of nearly $100 million to safely store their nuclear weapons.

Sanger writes that this underlines a central concern among foreign policy officials in Washington: The fear that nuclear weapons could fall into unsavory hands in Pakistan.