The concept: An Asian missile shield

When North Korea launched a three-stage missile over the North Pacific last August, a Reagan-era defense concept and a pair of military acronyms regained the luster of public prominence they'd lacked for more than a decade. Suddenly the idea of protecting wide areas (theater missile defense or TMD) and even the entire US (ballistic missile defense or BMD) from missile attack is back on the agenda. Last month, both houses of Congress passed resolutions calling such systems a matter of national policy.

Not only the United States is involved. An ability to defend against missiles is a weapon in itself, so Russia is warning that an American BMD shield will destabilize arms-control agreements to reduce the number of nuclear missiles in the world.

And China, whose Premier Zhu Rongji is visiting Washington this week, insists that TMD in East Asia will ignite an arms race.

Today the Monitor focuses on TMD - what the technology promises to provide, why the US and other countries want it, and why even the discussion of missile defense in Asia causes controversy.

THE TECHNOLOGY:

The concept is simple. Use radar and other means to detect an aggressor's rocket as it is taking off and then use a guided interceptor to shoot down the enemy missile before it does any damage. Hit a bullet with a bullet, in other words.

From that point forward, things get vastly complicated. With projectiles moving at incredible speeds and a margin of error of zero, putting the idea into practice hasn't been easy.

An Army-backed program to develop such a system failed its sixth test on March 29, although officials from the Pentagon and prime contractor Lockheed Martin Corp. voiced optimism about their efforts.

"Everything seemed to work very, very well with the exception, obviously, of what happened relative to the closing endgame for the missile," Lt. Gen. Lester Lyles, director of the US Ballistic Missile Defense Organization, told reporters. Officials said the "kill vehicle" missed the target by a mere 30 yards.

But the Pentagon has spent an estimated $50 billion, since the early 1980s, in developing this and other systems, causing critics to wonder if the "endgame" between missile and interceptor will ever get much closer.

Upper- and lower-tier systems

The TMD program is split between attempts to shoot down incoming missiles at a low altitude (about 12 to 15 miles) and "upper-tier" systems that try to hit the target when it is higher and farther away. The "lower-tier" programs, such as an advanced version of the Patriot missile used in the Gulf War, have had some successes, but they can cover only small areas, such as an airport or a military base.

The Army program tested last month is an upper-tier system, as is the Navy's Theaterwide Defense effort, technologies that would protect much wider areas.

The Theaterwide system, along with a Navy lower-tier system, would involve upgrading the capabilities of guided-missile cruisers and destroyers already afloat. These systems offer the advantage of easy mobility.

One defense-industry executive says that defending Japan from missile attack would require two of these advanced warships, and Taiwan would need only one.

THE THREAT:

North Korea's August missile launch took most of the rest of the world by surprise, but it seemed to underscore an official US report last summer that warned of emerging threats from "rogue nations."

North Korea says it launched a small satellite with a Taepo Dong three-stage rocket, although no other country has verified the existence of whatever went into orbit. Most worrisome to defense planners is that the missile showed that North Korea could put a warhead anywhere in Japan and, with upgrades, perhaps as far as Alaska or Hawaii.

North Korea is the bad guy of the moment, but the reality is that the country's Communist, xenophobic regime may not last as long as the decade it will likely take to develop and build TMD systems in East Asia. "North Korea provides a good excuse, but as a matter of fact the primary target is China," says Seizaburo Sato, a security specialist at the Institute for International Policy Studies in Tokyo.

Down the road

China's capabilities range from short-range rockets to intercontinental ballistic missiles tipped with nuclear warheads, so the country poses a threat near and far. Professor Sato notes that no country is willing to say as much out loud for fear of angering officials in Beijing who are already anxious about TMD.

Although they are now improving their relations, South Korea and Japan may be secretly seeing each other as threats down the road. When the two Koreas unify, something that most experts regard as inevitable since the two countries are mainly divided by outdated cold-war ideology, the product will be a militarily imposing nation. For one thing, the two sides have spent decades preparing to fight each other.

That realization hasn't escaped Japan or China. Conversely, South Korean strategists are reportedly citing Japan as a reason to develop and acquire a TMD capability. North Korea doesn't provide them with the "excuse" everyone else has, since the upper-tier defenses are no good against close-at-hand missile launch sites in the North. North Korea does pose dangers, especially since Western governments believe it has at least begun to develop nuclear weapons. But experts point out that TMD offers no real security against an attacker determined to deliver a nuclear, chemical, or biological device. By far the easiest way to strike using these weapons is to place one on a truck or a boat and move it near the target.

Putting the weapon on the tip of a missile is probably the most complex delivery system available.

THE CONTROVERSY:

For the moment, TMD is in the eye of the beholder. With no plans on paper for whom to include in the deployment of such a system and no reliable technology in hand to actually stop enemy missiles, the controversy is a debate over what might be.

But even a hypothetical missile defense system is enough to raise temperatures in Asia. The Chinese, in particular, have complained loudly and often about the development of TMD. Their major worry is the advantage that such a system could offer the island of Taiwan, which China sees as a renegade province that must eventually be brought under Beijing's control.

If the US includes Taiwan in a TMD system, "that will completely disrupt the current world situation, and instead a new cold war will appear," warns Wang Daohan, China's top negotiator on Taiwan issues. Other Chinese officials have said that TMD in Asia will force China and other nations to expand their missile capabilities.

Taiwan's perspective

Taiwanese officials, threatened by Chinese missiles just across the Taiwan Strait, are eager for TMD, even though they receive little support on the issue from Washington. Because they are trying to acquire the guided-missile destroyers that would be the basis for the Navy systems, they might only have to buy upgrades in order to have a TMD that more or less works alongside what the US would have.

At present only a few members of Congress - and no one in the US administration - have spoken up in favor of helping to protect Taiwan with the new technology.

Although Chinese leaders have denied a buildup, media reports citing intelligence sources have said that China is increasing the number of missiles it deploys near Taiwan. Military analysts question whether China has the strength to prevail in an invasion of Taiwan, but its missiles provide a constant source of political leverage over an island that must continually worry about Chinese intentions as it ponders whether to declare outright independence from China. A missile defense system would weaken Chinese leverage.

Future of Japan's military

But Taiwan isn't the only issue. Chinese and other Asian officials, who worry about the revival of Japanese militarism, treat any advance in Japan's military capability with suspicion. South Korea's initial rejection of TMD - although officials there are reportedly moving in favor of the idea - may have been a knee-jerk response to the prospect of Japan gaining a defensive advantage. Japan decided soon after the flight of the Taepodong to make further contributions to TMD development, although it is nowhere near ready to fund an actual system. Japanese officials say they are unconvinced that the technology will ever work as advertised.

Japanese leaders, bound by a "peace" Constitution drafted by US occupation forces just after World War II, are forced to think in purely defensive terms.

The country's Self-Defense Forces, for instance, have nothing that could be termed an offensive missile - a rocket that could put payload in another country.

But just last month, the country's navy fired its first shots in anger since the war when destroyers and other vessels pursued suspected North Korean spy ships that had been in Japanese waters.

The episode indicated the slow shift away from doctrinaire pacifism and toward more conventional thinking about defense and security. If that shift gains speed in years to come, the Japanese may become less convinced of the need to develop and deploy TMD. They may instead opt to deter future aggressors more cheaply - by acquiring some offensive missiles of their own.