Bob Cesca has done the work
of calculating the number of terrorist attacks under each of the last three presidents, along with the number of fatalaties during each administration.
Of course Obama has three more years to go, but I think Cesca's work is more than enough to debunk this idea that "George Bush kept us safe after 9/11. Or before 9/11. Or whatever delusional time warp Rudy Giulian is in today.