October 29, 2004 :: Analysis
Richard Garwin writes in the November edition of the
Scientific American on the need for missile defense efforts to be properly directed. He makes a number of good points about the ballistic missile threat, but his opposition to the means by which to meet that threat leaves questions unanswered. First, a summary of his main points:
- The gravest threat is not posed by ICBMs, but by short-range ship-launched missiles, against which the Ground Based system currently being deployed would be completely ineffective.
- Inexpensive countermeasures which can be released during the missile’s midcourse phase can confuse the sort of hit-to-kill interceptors being pursued.
- Boost phase intercept is therefore significantly better than midcourse; during its ascent, no countermeasures may be released.
- Boost phase intercept is possible with land based interceptors, if the threat comes from Iran or North Korea, where one may be able to have a land-based interceptor close enough to reach the missile in the short (~250 sec) ascent. These require very quickly accelerating interceptors, with burnout speeds of around 20g’s, which are certainly possible.
- Land-based boost phase intercept would be impossible against Russia and China.
- Space-based defenses, such as the Brilliant Pebbles interceptors or a space based laser, are the only type of boost phase interceptor that would be effective against Russian and Chinese interceptors.
- Space based defenses would not be invulnerable, and would be susceptible to anti-satellite weapons and by overwhelming the interceptors in a particular area by firing many ICBMs at once from a small region.
Garwin makes some very fine points about the weakness of a midcourse phase intercept system. His argument for the importance of boost phase intercept is similarly compelling. But in the end, Garwin seems to advocate only one form of missile defense: land-based boost phase interceptors, such as the KEI program currently being researched. He also comes down squarely against space based interceptors.
But the limitations of a land-based boost phase interceptor program—which Garwin himself admits—however, demand space based systems. Only space based interceptors will be capable of destroying Russian and Chinese ICBMs in their boost phase. Despite the strengths of Garwin’s arguments about the importance of boost phase systems and the threat from a ship launched missile, his opposition to space based systems is unpersuasive.
Garwin goes so far as to suggest that a preemptive strike by China on our space based interceptors would not cause human casualties, “and might not be considered an act of war by the international community.” If “mining” space or preemptively destroying U.S. defensive satellites is not an act of war, one at least has to admit problems with another argument typically put forward, that defensive missile interceptors in orbit constitute a “militarization” or “weaponization of space.”
Garwin’s main argument against Brilliant Pebbles-type interceptors is also the most tired: it would provoke an arms race of sorts, prompting Russia and China “to build additional long-range missiles” or more exotic anti-satellite weapons to overwhelm our defenses. Garwin at one point depreciates midcourse defenses because they are not cost effective. It is true that we should pursue the most cost-effective defense. And space is the arena in which we can best compete. We may have to orbit a number of interceptors, and take measures to guard against Chinese or Russian anti-satellite weapons. But the counter-systems China and Russia would have to develop would also be much more expensive than midcourse balloon countermeasures. Not only is it the case that Russia and China probably cannot afford to win such a defensive “arms race,” it is also arguably better to have an arms race consist of defensive weapons than offensive, even nuclear, ones. So much the better for conflicts to take place in space, which, to repeat Garwin’s words, “would not result in human casualties and might not be considered an act of war by the international community.”
In the end, Garwin puts forward a number of reasons why space-based defenses against Russia and China may, with some effort, be overcome. But nowhere does he advocate an alternative form of defense to meet this threat. Similarly, having put forward the ship-based threat to counter current midcourse efforts, he does not proceed to suggest any other means by which to counter that same threat. The most glaring omission of this piece, however, is that the space based interceptors which he worries may be overcome by Russia or China could effectively be used against a rogue state ship-launched missile.
(Article)» Archive of Garwin writings at FAS
» More stories on: Analysis, Policy, Space-Based Systems
» Missile system details for: Brilliant Pebbles, Ground-Based Interceptor (GBI), Ground-based Midcourse Defense (GMD), Kinetic Energy Interceptor (KEI)
