190509-M-IG936-0163 DARWIN (May 9, 2019) U.S. Marine Corps Lt. Col. Brian Clifton, commanding officer of the Aviation Combat Element, Marine Rotational Force – Darwin (MRF-D), gives a tour of an MV-22 Osprey tiltrotor aircraft to U.S. Ambassador Arthur B. Culvahouse Jr. at RAAF Base, Darwin, Australia, May 9, 2019. The Ambassador’s visit with MRF-D demonstrates the strength of the partnership between Australia and the U.S. and their combined presence in the Indo-Pacific region. (U.S. Marine Corps photo by Lance Cpl. Kaleb Martin/Released)