Nidal Malik Hasan explains himself.
In what must have been the most bizarre grand rounds the doctors involved will ever see, Maj. Nidal M. Hasan spoke about Muslims in the US military and what the Koran and hadiths say on the topic. (Grand rounds are typically one hour presentations on a medical topic. ie. colon cancer, H1N1 vaccination, stroke, etc. Not religious treatises.)
The Washington Post has the set of slides from Hasan’s grand rounds presentation. They are startling. The Rubin Report has a great discussion of the presentation but you really should view all of the slides yourself.
Basically, Hasan states very clearly that based on the Koran Muslims cannot serve in the US military and that it is his responsibility, as a Muslim, to fight those who kill Muslims. He explains abrogation and the “Verse of the Sword” and writes “We love death more than you love life!”
He killed American soldiers because he was following the instructions in the Koran. As a Muslim, it was his duty.
That’s what he said.