Freed U.S. nationals released in a prisoner swap deal between the U.S. and Iran disembark from an airplane at Fort Belvoir, Va., on Sept. 19, 2023. Jonathan Ernst/Pool/AFP via Getty ImagesFive Americans held as hostages by Iran have been returned to the United States following a political deal in which President Joe Biden agreed to unfreeze US$6 billion in Iranian funds held in South Korean banks in exchange for the prisoners. Hostage-taking has been frequently used by both states and insurgent