That would, in part, depend upon the reasons why these two jihadis committed this act of terrorism! Major Nidal Hassan was born in the U.S., but the roots of his evil come from the Middle East.
I think this book explains everything we need to know.
Chechen Jihad: Al Qaedas Training Ground and the Next Wave of Terror
Yossef Bodansky, the author whose #1 New York Times bestseller Bin Laden: The Man Who Declared War on America first introduced American readers to al Qaedas evil mastermind prior to 9/11, returns to sound an important alert. In this authoritative look at the roots of modern terrorism, Bodansky pinpoints the troubled region of Chechnya as a dangerous and little-understood crucible of terror in the struggle between East and West. Drawing on mountains of previously unseen intelligence from Islamist movements and other military and intelligence sources from throughout the Middle East, Russia, and Central Asia, Chechen Jihad offers an intimate and startling portrait of the jihadist movement that is astonishing in its detail and chilling in its implicationsincluding new insights into the Chechen jihadists secret role in fighting against U.S. forces in Iraq and Afghanistan. An authoritative work of reportage and analysis, Chechen Jihad also points to a new way forward in the struggle to face down the challenges of international Islamist terrorism.
http://www.amazon.com/Chechen-Jihad-Qaedas-Training-Ground/dp/B003JTHUGG