costello. along with poppy harlow in paris. there are many questioning where intelligence authorities aren t watching more closely the attackers? after all the suspected ring leaders was featured in an isis magazine back in february claiming he had traveled to europe. at one point u.s. authorities raised the red flag. and then there is salah abdeslam on the loose. he was subject to a routine check in austria back in september and in february questioned by investigators. this is a man believed to have a radicalized his 13-year-old brew brother. and then samy amimour. his father even went to syria to bring his son back but was unsuccessful. in light of those possible intelligence failures, could such failures happen in the united states? with me now again from paris,