Vietnam Arrival Defense Secretary James N. Mattis shakes hands with U.S. Ambassador to Vietnam Dan J. Kritenbrink upon arriving in Hanoi, Vietnam, Jan. 24, 2018. DoD photo by Army Sgt. Amber I. Smith SHARE IMAGE: Download Image: Full Size (0.7 MB) Tags: Travels , Pacific Command, James N. Mattis, SecDef, PACOM, Indo-Pacific Photo By: Sgt. Amber I. Smith VIRIN: 180124-D-SV709-0521.JPG Photo Gallery