The abrupt and unexpected end of the bipolar cold-war system was an exogenous shock for Washington’s policymakers as well as all leading scholars of international relations. The Soviet Union’s decision to withdraw its troops from Eastern Europe sparked an intense debate among scholars regarding the factors accounting for the peaceful end of the conflict. Since the late 1990s, many authoritative accounts have been written to explain the failure of the prevailing theoretical paradigms of IR discipline to predict the cold war ending as it did. Experts have shed light on a broad range of factors, but the role of the US’s Strategic Defense Initiative (SDI) has always remained a subject of a major controversy. The controversy arises from a widespread but misguided holistic assumption regarding the role of the SDI in ending the cold war. It is wrongly believed that the Soviet leaders lost the cold war because of their inability to meet challenges posed by the SDI. The misperception has persisted partly because of the lack of access to the Russian archives until recently. Part of the reason for this is a rising trend in American academic circles towards an ideologically driven interpretation of historical events. However, experts’ opinions differ widely about the exaggerated importance attached to the SDI. Several fundamental questions still remain unanswered. These include: how effective was the SDI programme in driving Gorbachev’s 1988 decision to renounce his vision of inevitable conflict between capitalism and socialism? Why did the Soviet Union agree to enter into an agreement with the United States on the elimination of intermediate-range nuclear forces? And how valid is the pro-SDI scientists’ assumption that the 1987 Intermediate-Range Nuclear Forces (INF) treaty marked an end to the US-Soviet military competition? The issue has gained increased importance in the recent years because, in the views of some security analysts, the SDI represented an earnest effort by the US to make nuclear weapons obsolete. What makes the SDI debate relevant in today’s world is the way it can help us understand many diplomatic questions surrounding the ballistic missile defence programmes. In 1983, US President Ronald Reagan initiated a very ambitious and costly programme, also known as Star Wars, to minimise the likelihood of missile attack on US soil from the Soviet Union. The plan involved developing a sophisticated anti-ballistic missile system to intercept incoming intercontinental ballistic missiles above the atmosphere in order to destroy them before they hit their targets. The advanced technological system required for this purpose included weapons like computer-guided projectiles, nuclear X-ray lasers, and subatomic particle beams — controlled by a central supercomputer system. The president’s initiative drew a lot of criticism because developing such a comprehensive missile defence system was a dangerous idea and could have endangered the global strategic balance. Even if the US were able to develop the capabilities to destroy the Soviet Union’s fleet of intercontinental ballistic missiles (ICBMs), it would have triggered a new phase of nuclear arms race. The SDI was violating many arms-control treaties already in place between the two superpowers, sparking fears of new conflicts. For instance, the anti-Ballistic Missile (ABM) Treaty of 1972 limited both the United States and the Soviet Union to ground-based missile defence systems. The 1967 Outer Space Treaty also banned the use of nuclear arms in space. Many American policymakers were also aware that the Star Wars programmes involved many risks and it eventually became even the most controversial defence initiative of the Reagan administration. The creation of a huge anti-ballistic missile system not only raised new tensions between the US and the Soviet Union but also failed to achieve any of its goals, costing US taxpayers more than thirty billion dollars. Even President Reagan recognised in one of his speeches that missile defence systems had limitations and, if paired with other offensive policies, could be seen as favouring an aggressive posture. One common misperception holds that by signing the INF Treaty and allowing for more intrusive verifications, Soviet leaders had formally exhibited their inability to counter the SDI. In fact, many years prior to the initiation of the SDI, Gorbachev had already revived the concept of peaceful coexistence, making it clear that he did not count on achieving victory in a nuclear war. Contrary to the pro-SDI argument that the idea of actually using nuclear weapons became officially unthinkable after 1983, the implementation of the SDI increased the chances of war. In 2009, David Hoffman wrote a very famous book ‘The Dead Hand’, concluding that the SDI had, in fact, extended the cold-war conflict. After getting access to Soviet archives, other Western scholars also found no concrete evidence pointing to the conclusion that the SDI had caused the Soviet Union to start strategic arms-control talks in 1984. Rather, the SDI became an unnecessary obstacle to negotiations because the sudden increase in defence expenditures during that time had made the Soviet Union sceptical of US intentions. Many Russian security experts also support the view that the SDI heightened Soviet fears. At the 1986 Reykjavik summit, between Soviet leader Mikhail Gorbachev and US President Reagan, Gorbachev was ready to give up the Soviet ballistic missile force, but the deal fell through because the US was not willing to accept limits on its missile defence programme. After this summit, the Soviet defence ministry assumed a very rigid position because the Reagan administration did not appear to be serious about reducing nuclear weapons and ending the arms race. More alarmingly, deploying strategic defences could also have made the Soviet leaders launch a sudden nuclear attack on the US. In a nutshell, the Strategic Defense Initiative hindered arms-control negotiations because, logically, offensive weapons reductions could not have been possible without reductions in defensive weapons. The application of this new technology, without any coordination with the Soviets, made the situation worse because the Soviets were afraid that their nuclear deterrent might even become ineffective soon. The missile defence system could never make the world a safer place to live, but it certainly added new dimensions to the nuclear arms race for decades to come. The writer is a US-based nuclear security analyst and can be reached at rizwanasghar5@unm.edu