mattis. this is the official swearing in at the pentagon. we find cnn's own chief national security correspondent jim sciutto. jim, general mattis was confirmed almost overwhelmingly, 98-1 in the u.s. senate. he is highly regarded by both democrats and republicans, and his fellow members of the military. i think a lot of people in the building in which you are right now breathed a sigh of relief when they heard mattis was being considered for the job. >> no question. deep respect for general mattis, and that is up and down the ranks. at the highest levels, but also enlisted men and women who served with him in iraq, earning that nickname "mad dog" during the fight for fallujah. as you know, a much deeper experience in mind, military mind, he's an educated man, a big thinker, an historian. so, that kind of wisdom really and experience, that weight give the people in this building