Carter that the false alarm was "fraught with a tremendous danger" and "I think you will agree with me that there should be no errors in such matters." In the months following the incident there were three more false alarms at NORAD, two of them caused by faulty computer chips. One of them forced the National Emergency Airborne Command Post to taxi into position at Andrews Air Force Base. 1980s 15 March 1980 A Soviet submarine near the Kuril Islands launched four missiles as part of a training exercise. Of these four, American early warning sensors suggested one to be aimed towards the United States. In response, the United States convened officials for a threat assessment conference, at which point it was determined to not be a threat and the situation was resolved. 26 September 1983 Several weeks after the downing of Korean Air Lines Flight 007 over Soviet airspace, a satellite early-warning system near Moscow reported the launch of one American Minuteman ICBM. Soon after, it reported that five missiles had been launched. Convinced that a real American offensive would involve many more missiles, Lieutenant Colonel Stanislav Petrov of the Air Defense Forces refused to acknowledge the threat as legitimate and continued to convince his superiors that it was a false alarm until this could be confirmed by ground radar. 7 to 11 November 1983 Able Archer 83 was a command post exercise carried out by NATO military forces and political leaders between 7 and 11 November 1983. The exercise simulated a Soviet conventional attack on European NATO forces 3 days before the start of the exercise (D-3), transitioning to a large scale chemical war (D-1) and on day 1 (D+1) of the exercise, NATO forces sought political guidance on the use of nuclear weapons to stem the Soviet advance which was approved by political leaders. NATO then began simulating preparations for a transition to nuclear war. These simulations included 170 radio-silent flights to air lift 19,000 US troops to Europe, regularly shifting military commands to avoid nuclear attack, the use of new nuclear weapon release procedures, the use of nuclear Command, Control, and Communications (C3) networks for passing nuclear orders, the moving of NATO forces in Europe through each of the alert phases from DEFCON 5 to DEFCON 1, and the participation of political leaders like Margaret Thatcher, Helmut Kohl and Ronald Reagan. The issue was worsened by