Looking back, it's easy to criticize Reagan's "Star Wars" program as impractical and perhaps even reckless. It never came close to helping rid the world of nuclear weapons as Reagan hoped it would, but the Strategic Defense Initiative (SDI) wasn't a complete bust. Many argue that SDI forced the Soviet Union to stretch its defense spending to the breaking point to match the United States' efforts, ultimately leading to the end of the Cold War.
SDI also forced a new round of negotiations on nuclear arms reduction between the two countries, culminating in the signing of the Intermediate-Range Nuclear Forces Treaty and the dismantling of thousands of conventional and nuclear weapons [source: Federation of American Scientists]. And while many people are quick to point out how slowly SDI progressed, President Reagan declared from the outset that a working missile defense might not materialize until the next century. We can only guess whether SDI would have started producing results throughout the '90s had it been continued.
We do know, however, that SDI fundamentally changed the United States' approach to missile defense. Since the "Star Wars" program was phased out in favor of more targeted and limited missile defense, the U.S. has continued to make slow and steady gains in its ability to destroy a small number of long-range missiles in flight. In 2011, the closest equivalent to SDI is the Ballistic Missile Defense System (BMDS) developed under the U.S. Missile Defense Agency designed to destroy the sorts of small-scale missile strikes that might originate from rogue nations and terrorist organizations. In addition to developing incredibly advanced tracking and targeting systems, the program has created both land- and sea-based missile defense systems. Working with Boeing, the agency has even found some success using plane-mounted chemical lasers to destroy a ballistic missile during its launch. So, while the technologies behind BMDS don't involve nuclear-powered space lasers and the like, the program would likely be far behind where it is today if it weren't for Reagan's dogged determination to build a missile defense system decades earlier.
What's more, the U.S. Missile Defense Agency is taking steps to carry out Reagan's vision of an international missile defense system. Currently, the agency is working with countries throughout the world on developing missile defense technology, installing tracking and detection systems, and creating support for the program. So while missile defense may never lead to a world free of nuclear weapons, some might argue that it's well on its way to making the world a safer place, and we have "Star Wars" to thank.