Before his two terms as US President (1981-1989), Ronald Reagan was a prominent actor, leading the Screen Actors Guild, and later serving as Governor of California. His presidency saw significant economic reforms, dubbed "Reaganomics," involving substantial tax cuts and deregulation. He strengthened national defence and adopted a firm stance against the Soviet Union, contributing to the Cold War’s conclusion. His Strategic Defense Initiative (SDI), a proposed space-based missile defence system, is referenced by the modern "Golden Dome" system. He also pursued arms control with Mikhail Gorbachev.