Flanked by physicist Edward Teller (left) and Lt. Gen. James A. Abrahamson, director of the Strategic Defense Initiative, President Reagan arrives to address a conference marking the first five years of the SDI program on March 14, 1988, in Washington. (Associated Press)

Flanked by physicist Edward Teller (left) and Lt. Gen. James A. Abrahamson, director of the Strategic Defense Initiative, President Reagan arrives to address a conference marking the first five years of the SDI program on March 14, 1988, in Washington. (Associated Press)