June 23, 2006: The pending test of the North Korean Taepo-Dong 2 ballistic missile has led to speculation about U.S. anti-missile systems. Why not shoot down the North Korean missile? It is a reasonable question, given the fact that a previous test launch sent another missile over Japan. But such a decision is not a simple one - taking a shot at the test launch would have consequences no matter the result.

There are some pros to taking such a shot. It would be a "real world" test of some American ballistic missile defense systems, including the Ground-Based Interceptors (GBI) based at Fort Greeley, Alaska and Vandenberg Air Force Base, California, that would be as close as they could get to a "real world" situation without an actual attack. A successful takedown of a missile would make the American ballistic missile defense system a very real consideration for China and North Korea, rendering their arsenal of ballistic missiles obsolete. It would go a long way towards blunting threats to American allies in the region.

That said, there are risks and problems with taking a shot at the North Korean test. First is the chance that the American effort to kill the Taepo-Dong 2 will miss. This would make for a lot of political hay for opponents of the system (which gets $7 to $8 billion a year for development). There is also the fact that Kim Jong-Il is not exactly the most predictable -or stable - person in the world, and this could lead to any number of consequences, including North Korean decisions to break off talks over the nuclear weapons program. Kim would most likely interpret U.S. interception of his ballistic missile test as an act of aggression. Also, it might take more than one shot to hit the missile - and the United States has a very small number of GBIs. Potential opponents would learn a great deal about the American missile-defense system - and such information could make the system's task harder in a real war.

The United States does not just have the GBI, though. There is another anti-ballistic missile that is in service as of September, 2004. This is the sea-based RIM-161A missile, also known as the Standard Missile 3 (or SM-3). The SM-3 has long range (over 500 kilometers) and able to hit targets up to 160 kilometers above sea level with a kinetic kill vehicle that uses infra-red guidance, which destroys incoming warheads with a direct impact, traveling at over 9600 kilometers per hour. The SM-3 fits into a Mk 41 vertical-launch cell, which is used on most surface combatants in the Untied States Navy (the twenty-two Ticonderoga-class cruisers and sixty-two Arleigh Burke-class destroyers equipped with Aegis).

The SM-3 is still undergoing some flight tests, but has already been deployed. In November, 2005, one flight test using an operational missile achieved a kill via a direct impact on a target. At least fifteen Aegis vessels in the United States Navy have been equipped to track intercontinental ballistic missiles, and at least three cruisers have been equipped to engage ballistic missiles, and Japan will be adding the SM-3 to its Aegis vessels as well (the Kongo and Atago classes of guided-missile destroyers). This gives the United States the ability to deploy a shield over an ally facing a threat from ballistic missiles. But overall, trying to intercept the North Korean test appears to have, for the United States, more downside than upside. - Harold C. Hutchison ([email protected])