Editor’s Note: The following piece is a reflection from Georgetown Professor David Koplow on the space law panel he moderated at our International Law Symposium on March 9, 2019.
The panel on “The Future of Planetary Defense and International Law” addressed the provocative legal, scientific, and policy questions regarding what should be done if it is discovered that a large asteroid is on a collision course with Earth?
This problem is significant because: a) we know that asteroids do strike the planet all the time, although most of them are too small to notice or care about; and b) an impact by a large asteroid could, depending upon its size, composition, and other factors, cause devastation on a local, regional, or even global scale. At the moment, there is no known such threat on the horizon, but astronomers acknowledge that they are currently unable to detect, identify, and track a large number of potentially hazardous objects. Even more worrisome, humans have no tested, reliable, in-place capability for promptly and effectively responding to such a danger, especially if it were detected with little advance warning time.
In response, NASA and its counterpart space agencies in other countries have undertaken efforts to survey the population of near-Earth objects and to develop techniques that could be employed to deflect a dangerous intruder. Sophisticated experiments are underway or planned to study the nature and characteristics of asteroids and to explore mechanisms for altering their trajectories – but these are far from completion.
Although the subject of planetary defense lies overwhelmingly within the realm of science and technology, there are interesting and important legal aspects, too, and the panel addressed two of special note.
The first legal conundrum arises from the possibility that one conceivable technique for attempting to alter the trajectory of an oncoming asteroid would be to employ the vast power of a nuclear explosion on, inside, or near it. Indeed, if the warning time were short, that may prove to be the only effective deflection technique. However, key provisions in some important, long-standing, and widely-adhered-to treaties stand in the way. These instruments were crafted with problems vastly different from planetary defense in mind – they were designed to pre-empt a nuclear arms race in space, and they have proven remarkably successful in foreclosing what could otherwise have developed into a dangerous and destabilizing exoatmospheric competition. The difficulty in reconciling these very distinct types of objectives – dodging an oncoming asteroid and foreclosing additional military applications in space – may prove to be a severe international challenge.
A second principal legal issue arises from the possibility that an attempt to divert an asteroid might, unfortunately, prove to be only “partially” successful. Suppose that the human intervention was unable to maneuver the asteroid sufficiently to make it miss Earth altogether, but did serve to alter its trajectory somewhat, so that it impacted Country X, instead of Country Y, where it would have struck if nothing had been done. Under applicable treaties, a country has “absolute” liability for damage caused on the surface of the Earth by its activities in space. That legal standard could result in an enormous exposure – the state(s) that in good faith exercised their best efforts to try to save the planet from an impact might incur an enormous financial responsibility for all the harm suffered by Country Y.
The most promising route considered by the panel for addressing both these legal issues is to exercise the powers of the United Nations Security Council. Under Chapter VII of the U.N. Charter, the Security Council holds a unique law-making ability, and possesses the authority to supersede the provisions of other treaties. If prompted by a genuine emergency, the Security Council could therefore authorize states to exert their best efforts for planetary defense, notwithstanding the provisions of the arms control treaties and it could likewise modify the usual liability standards. Of course, it will not be easy or automatic to draft suitable provisions that would deftly address the dangers and the costs without unleashing an unwanted arms competition and without leaving Country Y to fend for itself in response to a catastrophe.
David A. Koplow, Professor of Public International Law and National Security Law at Georgetown University Law Center
