History of Vietnam since 1945 unstable as no government could keep power for long. There were more coups, often more than one every year. The Communist-run Viet Cong expanded their operation and scored some significant military victories during this period. In 1965, US President Lyndon Johnson sent troops to South Vietnam to secure the country and started to bomb North Vietnam, assuming that if South Vietnam fell to the Communists, other countries in the Southeast Asia would follow, in accordance with the domino theory. Other US allies, such as Australia, New Zealand, South Korea, Thailand, the Philippines, and Taiwan also sent troops to South Vietnam.
What Happened to Us the song which features Stan Walker, was released on 29 May 2011. "What Happened to Us" charted on the ARIA Singles Chart at number 14 and was certified platinum by the Australian Recording Industry Association (ARIA). An accompanying music video was directed by Mark Alston, and reminisces on a former relationship between Mauboy and Sean. "What Happened to Us" was written by Josh Alexander, Billy Steinberg, Jeremy Skaller, Rob Larow, Khaled Rohaim, Israel Cruz and Jay Sean. It was produced by Skaller, Cruz, Rohaim and Bobby Bass. The song uses C, D, and B minor chords in the chorus. "What