Read an April 19, 2013 New York Times article by columnist Charles Blow on the trail of clues the brothers left behind.

Paul Marshall is a senior fellow at the Hudson Institute’s Center for Religious Freedom in Washington, D.C., and has written or edited many books about religion and politics. He served as editor and contributor for Radical Islam’s Rules: The Worldwide Spread of Extreme Sharia Law.

Douglas Pratt is a Professor of Religious Studies in the department of Philosophy, Religious Studies, and Ethics at the University of Waikato, Hamilton, New Zealand. His areas of expertise include Christianity, Islam, Christian-Muslim relations, interreligious dialogue, and religious issues such as pluralism, fundamentalism and extremism.

Read a May 22, 2012, story published on CNN.com about President Barack Obama’s plans to withdraw U.S. and NATO forces from Afghanistan.

Read a June 12, 2013, story published on BBC.com that covers Gen. Joseph Dunford request for continued support from international forces to support human rights and the democratic process in Afghanistan.

Read a Feb. 10, 2013, story published on BBC.com that takes a look at Afghanistan through the eyes of Gen. John Allen just after he resigned from his post as commander of U.S. and NATO forces in Afghanistan.

Read a July 18, 2011, story published on CNN.com that covers Gen. Petraeus’ resignation from the commander of U.S. and NATO troops in Afghanistan. Marine Corps Gen. John Allen took command after Petraeus.

Read a March 2, 2011, story published in the New York Times about the NATO airstrike that killed 9 Afghan civilians while Gen. David Patraeus was in command.