A U.S. aircraft carrier arrived in the South Korean port city of Busan on Friday for the first time in nearly five years to join naval exercises in a show of strength amid concern North Korea may conduct what would be its seventh nuclear test and first since September 2017.The arrival of Ronald Reagan, with nearly 5,000 crew on board, and warships from its accompanying strike group comes after North Korea adopted legislation detailing its policy on the use of nuclear weapons earlier this month.Stressing the "watertight" relationship that the United States and South Korea have had as allies …READ FULL ARTICLE