though, new terror concerns as we approach the first anniversary of the daring raid that led to the death of osama bin laden. there is no credible information suggesting al qaeda or its allies are planning attacks tied to the anniversary. but the concerns are real enough that president obama reviewed the threat picture just this morning with this top national security advisers. our pentagon correspondent chris lawrence is here with the details. what is the biggest threat intel officials are most worried about. they are very concerned right now about a renewed effort to target western aviation. in fact, the fbi, homeland security, and the u.s. military s northern command sent this memo out to law enforcement agencies across the country. basically alerting them to the possibility of this threat. specifically, they think the biggest threat is coming from al qaeda in the arabian peninsula. that is the most active al qaeda group. it s also the group that has tried to attack to u