The nature of the beast

Late word coming in is that an American Marine – who is also a Muslim – was (somehow) lured away from his post and is now held hostage by the Islamic fanatics:

"I'm also Muslim, but despite this they didn't release me," he said, bowing his head. "They are going to cut the head of any person regardless of whether he is a Muslim or not."

Doesn’t the Koran specifically proscribe against killing a Muslim? They don’t care. They have no country, no religion, no philosophy. They only live to hate.