as al qaeda's top operational planner and one of the only remaining figures in al qaeda's leadership who could serve as both an ideological guide and the operational leader. that was until u.s. officials say he was killed last week by a cia drone strike in pakistani tribal region dealing al qaeda another major blow. nearly ten years since 9/11, u.s. officials are now sounding cautiously optimistic that a strategic defeat of al qaeda could be near. for most of the past year rachel has been working with nbc news chief foreign correspondent richard engel about not 9/11 itself, but the decade after, how 9/11 has changed the country, what we've done and what we've done different now because of it. here now is a short clip from the piece, take a look.