Former U.S. Defense Secretary, Leon Panetta, says the attacks on Charlie Hebdo weekly in France were the result of an intelligence failure. The 2 brothers who conducted the attacks were already on a U.S. no-fly list. The U.S. has already alerted European authorites to about 3000 European citizens, about 1000 from France, who went to Syria to fight with Islamic State. Panettta says there is much room for improvement when it comes to tracking of individuals returning from conflicts in the Middle East, and making certain that the U.S. and Europeans are at the top of their game when it comes to security. Operationally the U.S. and Europeans need to be working together and being aggressive about individuals who have a history in these places in the Middle East.