Where Congress Veers Off Target

CONGRESS recently took a one-two punch at efforts to keep America safe from nuclear threats. The Senate delayed ratification of START II, the treaty that slashes the nuclear arsenals in both Russia and the United States, but it pushed through a bill that mandates the deployment by 2003 of a National Missile Defense System. This ring of bases would cost at least $35 billion and require hundreds of interceptor rockets, dozens of new radars, ground systems, and a new constellation of military satellites.

Neither move makes much sense. Arms control agreements - including START II - can verify the destruction of much of the former Soviet arsenal, helping to defuse this menace. This process could come to a screeching halt if Russia believes that the US plans to construct a cold-war-style missile defense. For this reason, Sen. Sam Nunn (D) of Georgia cast his first-ever vote against a defense authorization bill, calling the missile plans ''a supreme folly.'' But hard-liners were adamant that a new crash program was needed to protect the US from North Korea, Libya, Iran, and Iraq.

For example, House National Security Committee chairman Floyd Spence (R) of South Carolina cited the North Korean and Iranian threat. Sen. Jon Kyl (R) of Arizona said Palestinian terrorists could acquire a nuclear weapon by the end of the decade. Rep. Robert Dornan (R) of California summarized: ''It is hardly controversial to assert that it won't be all that many years before a pirate in a place like Baghdad or Pyongyang gets hold of a nuclear bomb and the means with which to deliver it. When that capability exists, it will of course be too late to start slapping together a national missile defense.''

Is there really a threat? None of those small countries has missiles that can reach the US, and the lessons learned from decades of American space efforts indicate that it is far from an easy task to develop them.

Missiles, like airplanes, come in many sizes. Many countries can build Cessnas, but only a few can construct 747s. Most nations with missiles have only short-range models like the Scud used in the Persian Gulf war. The single stage of a Scud puts out a thrust of 13,000 pounds, propelling the rocket about 300 kilometers at a maximum speed of .5 km per second. America's three-stage Minuteman III, with 202,600 pounds of thrust, delivers a warhead over 13,000 km away at speeds of 7 km per second.

Huge leaps in technology and finances are necessary to build modern aircraft or missiles capable of traveling across the oceans. This is why the Central Intelligence Agency notes that only two countries, China and Russia, have the capability of striking the US with ballistic missiles from their territories. Moreover, the CIA says the probability is low that any other country will acquire this capability during the next 15 years. North Korea, for example, would require at least 10 to 15 years to develop an ICBM with a nuclear warhead. But even that is doubtful. North Korea spends $2 billion to $5 billion a year on its military. Over the past 40 years, the US spent $180 billion on its missile fleet and $24 billion more for warheads.

Finances aside, propulsion technology limits any nation's ICBM ambitions. Scud missiles can be built from steel or aluminum, with basic guidance systems and crude warheads. Longer-ranges or space orbits, however, require weight savings that simple steels and aluminum cannot provide, yet the vehicle must also withstand greater vibration and temperatures over a longer period of time. Simply ''stretching'' Scuds, as the Iraqis did during the Gulf war, produces serious problems and only marginal-range gains. The ''al-Hussein'' Scuds frequently broke up on reentry.

There are also formidable computerized guidance obstacles. Since ballistic missiles are only powered in the first 10 to 20 percent of flight, they must be targeted at exactly the right speed and position long before reaching their destination. Only the most advanced computerized systems can remain accurate while undergoing the higher acceleration and extreme temperature changes that a 10,000 km ICBM flight path requires, compared with a medium-range 1,000 km flight.

Difficult problems also confront a country trying to short-cut this process by converting commercial space launch vehicles to ICBMs. The CIA estimates that although it would take a technologically advanced country less than two years to convert a space launcher into a surface-to-surface missile, it would take about 10 years for Iran, Iraq, North Korea, or Libya to build a reentry vehicle, the container which protects and delivers the warhead, capable of withstanding the high temperatures, G-forces, and vibration of reentering the atmosphere. More technological hurdles must be overcome to develop ground systems, like silos and communications setups, to protect and deliver the missiles on target.

Even companies with long experience building ICBMs have difficulty building new space launchers. In the last two years, the best and biggest in the field have suffered more than 10 launch failures. Last year, the evening news featured dramatic footage of a rocket built by EER Systems pinwheeling out of control on its maiden flight. Similar failures befell Lockheed Martin's new LLV and Orbital Science's Pegasus launchers.

Still, North Korea's test last year of a 1,000 km Nodong missile (a stretched Scud) demonstrates that despite these challenges, some countries are trying. Fortunately, ICBM development requires numerous tests over several years, easily detected by US surveillance systems. Moreover, if the US were to be threatened by a missile-equipped third-world foe, all these facilities are easily targetable by aircraft and cruise missiles that could intercept any missile before launch.

In an era of finite defense budget resources, is a crash program for a National Missile Defense System our highest priority? A balanced approach of vigilance, reductions of existing nuclear missile stockpiles, continuing controls on technology exports, and continued research on the technologies that might eventually be used in missile defenses, without an arbitrary deadline, is a far more fiscally prudent and militarily sound plan.