12 June 2018—The world awakens to an international crisis: officials at the Tokyo airport have detained a foreign airliner suspected of carrying illegal arms. The aggressive and threatening response from the plane's country of origin, a "rogue" state believed to possess both nuclear and biological weapons, adds credibility to the suspicion. Hamstrung by its rogue status, the country's economy has been in free fall for decades, and with this latest incident, it's widely feared that the country will launch a nuclear attack against Japan. U.S. satellites report escalating activity at the country's rocket-launch facility; other U.S. intelligence indicates that three intermediate-range missiles are being fueled and are within a 15-minute launch window. No air-, sea-, or land-based military system is available to respond in time. The U.S. president demands that the country cease and desist immediately but receives no response. Five minutes later, the U.S. Strategic Command activates a heretofore undisclosed space-based laser; within minutes, it incinerates the launch facility's command and control center, thus narrowly averting a catastrophe.

Today, such a scenario is science fiction, but it—or something like it—could become reality within the next decade or two. The irony is that the economic and political price the United States would have to pay to bring about such a system, even if it could be done, might well outweigh its military benefit.

No country today is known to have weapons deployed in space, and many countries oppose their development. However, at least some U.S. Pentagon officials have been arguing that the United States must now, after decades of debate, develop and deploy offensive space weapons. In fact, over the past 10 years, the U.S. government has spent billions of dollars researching and testing such weapons. If deployment became official U.S. policy, such a step would have profound—and, we feel, profoundly negative—implications for the balance of global power.

The United States itself, our analysis suggests, would discover that the military advantages that might be gained from space-based weapons are outweighed by their political and economic costs. Deploying such weapons would also create new, asymmetric vulnerabilities to U.S. armed forces, as we will describe in this article. In addition, it would be a significant political and strategic departure from 50 years of international law and diplomatic relations.

The U.S. and North Atlantic Treaty Organization (NATO) militaries already make extensive use of space-based systems. Satellites revolutionized conflicts such as Operation Iraqi Freedom, letting U.S. aircraft fly one-third the number of sorties and use one-tenth the number of munitions that they had expended just 10 years earlier in the Persian Gulf War. That economy was largely due to the great increase in accuracy offered by space systems.

Satellites are now routinely used to detect, identify, locate, and track targets. They also provide mobile, secure communication links between military control centers and theaters of operation; near-real-time imaging; signals intelligence; and meteorological data. And, of course, the constellation of Global Positioning System (GPS) satellites ensures that military personnel need never be lost amid a war's chaos.