advocacy for nuclear energy development, a strong nuclear arsenal, and a vigorous nuclear testing program. He was a co-founder of Lawrence Livermore National Laboratory (LLNL), and was both its director and associate director for many years. In the 1980s, Teller began a strong campaign for what was later called the Strategic Defense Initiative (SDI), derided by critics as "Star Wars," the concept of using ground and satellite-based lasers, particle beams and missiles to destroy incoming Soviet ICBMs. Teller lobbied with government agencies—and got the sanction of president Ronald Reagan—for a plan to develop a system using elaborate satellites which used atomic weapons to fire X-ray lasers at incoming missiles—as part of a broader scientific research program into defenses against nuclear weapons. Teller's own comments on the role of lasers in SDI, as disclosed in live panel discussions, were published, and are available, in two laser conference proceedings. The Strategic Defense Initiative was created by U.S. President Ronald Reagan on March 23, 1983 to use ground and space-based systems to protect the United States from attack by strategic nuclear ballistic missiles. Supporters of SDI claimed it helped contribute to the fall of the Soviet Union by the so-called strategy of technology, which was a prevalent doctrine at the time. While SDI was a source of disagreement between the United States and the Soviet Union a summit led to the Intermediate-Range Nuclear Forces Treaty, which some have claimed was an outgrowth of USSR's Mikhail Gorbachev's fear of SDI. In 1991 president George H. W. Bush shifted the focus of SDI from defense of North America against large scale strikes to a system focusing on theater missile defense called Global Protection Against Limited Strikes (GPALS). In 1993 president Bill Clinton changed its name to the Ballistic Missile Defense Organization (BMDO) and its emphasis was shifted to theater missile defense and from global to regional coverage. BMDO was renamed to the Missile Defense Agency in 2002. Stanislaw Ulam Stanislaw Marcin Ulam (1909–1984) was an American mathematician of Polish Jewish origin, who participated in the Manhattan Project and originated the Teller–Ulam design of thermonuclear weapons. He also invented nuclear pulse propulsion and developed a number of mathematical tools in number theory, set theory, ergodic theory and algebraic topology. Ulam was born in Lwów Galicia to a wealthy Polish-Jewish banking and timber-processing family who were part of the large Jewish minority population of the city. Lwów