Nemesis: The Last Days of the American Republic

decoys along with Soviet missiles and increasing the number of missiles in any assault. There was no reason, he said, to waste money trying to match an American ABM system.⁴⁶ Twenty years later, nothing has happened that would alter his conclusion in any way.

In the weightlessness of outer space, a decoy cannot be detected simply because of its lighter weight. Some experts believe that the new X-band radars and the sensors mounted on our interceptors will sooner or later be able to detect an infrared signature that would distinguish a warhead from a decoy, but there is no test evidence to support this belief.

Professor Theodore C. Postol of MIT, one of our country’s leading authorities on ballistic missile defenses, has been warning about the problem of decoys for many years. In a now famous June 15, 2002, letter to the Boston Globe, Postol wrote: “The current National Missile Defense interceptor tries to identify warheads and decoys by ‘looking at them’ with infrared eyes. Because the missile defense is essentially using vision to tell which objects are decoys and which are bombs, this technique is no more effective than trying to find suitcase bombs at an airport by studying the shape and color of each suitcase.” He concluded: “The [Missile Defense] agency has no technical program for solving this fundamental problem. It has also been unable to provide any credible scientific evidence or analysis to show that it can ever solve this problem. So what it proposes to do is to classify the fact that the targets it is flying [in tests] have been preconstructed in ways that will allow it to tell one from another. This misuse of the classification system to hide the fact that the National Missile Defense System has no credible scientific chance of working is a serious abuse of our security system.”

The decoy problem is one of the reasons why the Pentagon has begun to invest heavily in a boost-phase intercept. This form of attack—while the incoming rocket and its warhead are still coupled and moving relatively slowly into space—would destroy any decoys before they could separate from the missile, thereby solving that problem. There are at least fifty different proposals for developing boost-phase interceptors, but all of them suffer from a fundamental inability to tell whether a missile just after liftoff is carrying a warhead or is merely launching a satellite. In addition, most forms of boost-phase attack, particularly lasers, would not be able to fully disable the warhead, which will surely be heavily shielded and thermally insulated in order to be able to withstand re-entry into the Earth’s atmosphere. The danger is that an attack on an ascending rocket will merely knock it off course, causing it to fall back into a neighboring, possibly friendly, country. For example, a missile launched from Iran against Washington, D.C., and attacked in its boost phase would threaten several Middle Eastern countries as well as Turkey and possibly even Europe.⁴⁷ Air force officers and members of the Center for Security Policy do not allow such considerations to worry them, arguing that “collateral damage” may be unavoidable to protect the United States.

There has been a great deal of writing about a space-based boost-phase antimissile laser, but it is at present little more than a concept and would almost surely be too heavy ever to put into orbit. The main research focus for a boost-phase weapon is an airborne laser (ABL). Mounted in the nose of a modified Boeing 747-400F commercial airplane, the ABL’s high-energy laser is expected to be in the megawatt range—more than a million watts. When working properly, the laser would fire a beam of directed energy at the speed of light toward the body of an ascending rocket that might be hundreds of miles from the aircraft, heating its shell until it failed structurally. Whether such a laser would actually produce enough energy is still an open question. The chosen source of directed energy is a chemical oxygen iodine laser that produces energy through the reaction of hydrogen peroxide with chlorine gas. According to Miranda Priebe, a physicist and a research assistant at the Center for Defense Information, “The ABL beam will be generated by several laser modules. When light from these modules is amplified with a resonator (a set of mirrors that must be able to withstand the intense energy of the laser beam), the combined output is a single, powerful beam.”⁴⁸

On December 3, 2004, the prototype ABL aircraft had its first two-hour flight aborted by Missile Defense Agency officials after twenty-two minutes because of a false warning from on-board instruments of an air-pressure problem. Boeing, Northrop Grumman, and Lockheed Martin share the work with the agency. The ABL’s price is now in the range of $5.1 billion for one fully equipped airplane, twice the original estimate. On March 9, 2005, Lieutenant General Henry Obering, director of the Missile Defense Agency, told the press that the ABL “is not out of the woods yet. I can’t declare that [it is] a totally risk free program.”⁴⁹ His remark was a major understatement.

Leaving aside the fact that putting a high-energy laser aboard an aircraft involves fitting an incredible array of sensors, computers, chemicals, and mirrors into a constricted, dusty, vibrating space, a major problem is weight. The original plan called for fourteen SUV-sized modules working in tandem to generate laser light that would be projected through a telescope mounted in the 747’s nose. However, that idea proved to be impossible, so the number was cut to six modules. Even the six-module system weighs about 180,000 pounds—5,000 pounds more than the original design weight for the fourteen-module scheme—and still puts pressure on the airframe. The Boeing 747-400 freighter, the largest commercial cargo transport in service, can carry a maximum of 248,000 pounds, but this weight has to be distributed throughout the aircraft. The laser consists of six large machines lashed together on the main deck plus chemicals and crew to monitor the laser resonators. In addition, it was discovered on the 2004 test flight that the laser beam ignites dust particles in its path. These produce flickers of visible light called “fireflies,” which weaken the beam’s overall energy. The Missile Defense Agency has decided that the ABL cannot be used at lower altitudes where dust is plentiful, which of course radically reduces the time available for an interception. Similarly, the first flight revealed problems of airframe vibration and atmospheric turbulence that generate what is called “jitter,” which also impedes the laser beam and produces wear and tear on the delicate equipment.

Finally, the heavily laden Boeing 747 lumbers through the sky at a slow speed and is incapable of defending itself. It would thus require fighter aircraft protection in a combat situation, which in turn would necessitate the presence of aerial refueling tankers. It seems likely that any organization adept enough to build an ICBM carrying a weapon of mass destruction could also field a surface-to-air missile, such as the one that, on May 1, 1960, shot down Francis Gary Powers’s U-2 spy plane over Sverdlovsk, Russia, at 70,500 feet.⁵⁰ It is hard to imagine how an ABL lurking within the necessary hundreds of miles of a launch site with a boost-phase interception in mind could be effectively protected, something that will not be lost on an ABL 747’s aircrew.

Terminal-phase interception is not much more promising than the ABL, but at least it is not so esoteric. The chief problem is not detecting the warhead as it re-enters the atmosphere, which is comparatively easy, but designing a missile fast enough to catch it and collide with it in the one or two minutes available. The main weapon the United States proposes to use for this purpose is the Patriot PAC-3 (Patriot Advanced Capability), manufactured by Lockheed Martin Missiles and Fire Control of Dallas, Texas. The PAC-3 is an improved version of the Patriot missiles used during the first war against Iraq in 1991 with such dismal results. (They failed to bring down any Scuds Iraq fired at General Schwarzkopf’s forces or at Israel.) The new one is, however, much faster and without the heavy explosive warhead of its ancestor. PAC-3, however, was never designed for defense against an ICBM warhead but rather for downing shorter-range tactical and cruise missiles. Using a solid propellant rocket motor, the PAC-3 flies at great speed to an intercept point specified by its ground-based fire-solution computer and destroys the target by colliding with it.

According to former assistant secretary of defense Philip Coyle, “Although [the PAC-3] appeared to be doing well in development tests— hitting ten out of eleven targets—those early tests involved the usual artificialities of preplanned intercepts. In more realistic operational tests conducted [in 2002], the PAC-3 hit only three targets out of seven tries, or less than 45 percent.”⁵¹ The main problem with terminal defense is that it can, by definition, protect only a limited area, such as a city. To be effective we would have to deploy innumerable terminal-defense systems all over the country. The deliberate destruction of an atomic weapon over a city or other site might also produce massive nuclear fallout, which could be extremely damaging to the defending country.