Michael Richardson: Korean firings put focus on missile defence

Reports yesterday that North Korea had test-fired missiles including a Taepodong-2 with an estimated range of at least 6000km - enough to hit Alaska and a small part of the western United States - has refocused attention on efforts to develop an effective system for destroying incoming ballistic missiles.

As the firings became imminent, the Bush Administration put its ballistic missile defences on alert. This system consists of an array of missile interceptors based on land and soon on surface ships. By 2010, it may include airborne lasers on modified Boeing 747s. All will be linked by advanced tracking and command systems.

However, the system is still being developed and has limited operational capability.

There are doubts whether it could intercept and destroy a single long-range Taepodong-2 missile, let alone a flight of several missiles. Unless a North Korean missile was thought to be armed, it is very unlikely the US would even try to shoot it down.

Moreover, critics say the ballistic missile defence system is too expensive and so technically challenging that it will never provide a reliable shield, especially against long-range missiles travelling at many times the speed of sound carrying warheads that can release decoys and take other countermeasures.

Still, Tokyo and Washington are anxious to be seen to be strengthening their missile defences. Some shorter-range parts of the system are reasonably well proven, among them the Patriot land-based interceptor missile and the sea-based Standard missile. No Government wants to be accused of allowing its country to be held hostage to missile blackmail.

Tokyo and Washington said last week that they had agreed to deploy new Patriot interceptor missiles by the end of the year at US bases in Japan for the first time. Tokyo already has permission to produce the US-designed Patriot Advanced Capability-3 (PAC-3) surface-to-air missiles in Japan so they can be installed at Japanese military bases this year.

Earlier, the two allies agreed to strengthen their co-operation on missile defence.

Lockheed Martin, maker of the PAC-3 interceptor, says it had hit the target missile 10 out of 14 times by the time operational testing was finished in 2002. It says the interceptor successfully engaged several ballistic missiles during combat in the Iraq war. Unlike the older Patriots fired during the earlier Gulf War with mixed results, the PAC-3 does not carry an explosive warhead. Instead, it is programmed to hit and pulverise an incoming ballistic missile.

The US and Japan have also sent several of their Aegis warships into international waters off North Korea to detect and track any Taepodong-2 launch. The Aegis radar system can track enemy missiles and guide outgoing weapons. Two US Navy Aegis cruisers have been armed with the Standard Missile-3 (SM-3). However, they will not be operational until late this year. Other US and Japanese warships with SM-3 interceptor missiles will follow.

The US military says it has shot down incoming test missiles with the SM-3 in seven out of eight attempts. The latest successful intercept of a dummy warhead after it separated from the booster rocket was last month off Hawaii.

The US divides missiles into four range classes: Intercontinental ballistic missiles (ICBM), over 5500km, like the Taepodong-2, although yesterday's firing appears to have been aborted very early into the flight; intermediate-range, 3000-5500km; medium-range, 1000-3000km; short-range, up to 1000km.

The land-based PAC-3 batteries and the seaborne SM-3 missiles are designed to hit short-range to medium-range missiles, but not ICBMs like the Taepodong-2.

North Korea in 1998 fired a Taepodong-1 missile over Japan into the Pacific, saying it was carrying a satellite, not a dummy warhead. Nonetheless, the test prompted Tokyo and Washington to step up co-operation to build missile defences.

Missiles that North Korea has tested can reach all parts of Japan within 15 minutes of launching.

The Taepodong-2 ICBM had never previously been flight-tested by North Korea. But US officials believe the multi-stage rocket recently prepared could have a range of 8000 to 12,000km.

America plans to give the sea-based Aegis system the capability to hit ICBMs. But for the moment, US protection against a one-off or limited long-range missile attack rests on just nine ground-based interceptor rockets in silos in Alaska and two more in California. Seven more interceptors are planned for Alaska by the end of the year.

They would be fired at an incoming ICBM while it was high above the earth in outer space in the mid-course phase of its arc-like trajectory. This phase can last up to 20 minutes, allowing several chances to destroy a nuclear, biological or chemical warhead after it has separated from the booster rocket and while it is still outside earth's atmosphere.

However, hitting a missile warhead travelling at over 24,000km/h with an interceptor going more than 11,000km/h is a huge technical challenge. So far, the US has managed only five hits out of 10. The last successful test was in 2002, although the Pentagon says problems that plagued more recent tests have been fixed.

The prospect of being threatened by long-range missiles from North Korea or Iran is anathema to the Bush Government. So it is spending as much as US$9 billion a year to improve ballistic missile defence.

The next advance it hopes to make is to use modified Boeing 747 jumbo jets, armed with powerful laser guns and sophisticated sensors and tracking devices, to destroy long-range rogue missiles anywhere in the world within the first five minutes of their flight, when the launch rocket is still gaining speed and countermeasures to protect it are less effective.

A successful early strike against a missile in 'boost' phase, when it is easier to track, would take place before it could release biological or chemical weapons in many small warheads to overwhelm defences, or a nuclear warhead protected by decoys or specially cooled to confuse interceptors using heat-detection sensors.

But these airborne lasers will not be operational for at least three years, leaving the US potentially vulnerable to its two 'axis-of-evil' enemies - North Korea and Iran - which have been co-operating to develop an effective ICBM strike force.

* The writer, a former Asia editor of the International Herald Tribune, is a visiting research fellow at the Institute of South East Asian Studies.