Missile Creep.(International Edition; SOUTH KOREA)(ballistic missile defenses)

Byline: Fred Guterl

A weapon built to defend ships from planes has morphed into Star Wars.

Kim Jong Il is obviously uncomfortable. As tens of thousands of U.S. and South Korean troops staged an annual war-games exercise last week, he put North Korea's military on alert. The real pea under his mattress, though, could be four battle cruisers that ply the Sea of Japan, just over the horizon from the Dear Leader's beaches. These ships--two American, two Japanese--carry missiles capable of reaching North Korean nuclear-tipped rockets on their way to Japan, or even the satellite Kim has promised to put up any day now. U.S. Admiral Timothy Keating may have had these same missiles in mind when he threatened in late February to shoot down anything Kim felt emboldened to launch.

These four cruisers aren't the only ships that act as a de facto antimissile defense. The U.S. Navy has 73 Aegis ships around the world equipped with missiles that can reach space targets--whether the intercontinental ballistic missiles (ICBMs) that carry nuclear warheads or satellites that fly in low earth orbit. As the Obama administration shows signs of backing away from plans to put missile defenses in Poland and the Czech Republic, this fleet of "Aegis" cruisers, as they're called, may be called upon to take up the slack. U.S. Representative Ellen Tauscher, head of the House strategic forces subcommittee, praised recent progress on Aegis in hearings last month. "This was a major accomplishment that we should all take pride in," she said. "The same cannot be said of the long-range" ground-based missile defense. However, there are reasons to doubt that relying on Aegis will be an effective military strategy in the long run.

Compared with land-based missile defense, Aegis has the advantage of proximity. Ships can go, with minimal diplomatic hassle, wherever the threat is greatest. Kim's saber rattling, in fact, led the United States to supply Japan with Aegis equipment and know-how. Aegis, a combination of radars and interceptor missiles, was originally designed to defend battle cruisers against fighter jets. Technological improvements over the years gradually extended its range. The Bush administration funded a new interceptor--SM-3, for "standard missile"--capable of reaching the ICBMs Russia and China have and North Korea and Iran want. Tests suggest that it can fly fast and far enough to catch an ICBM shortly after leaving the atmosphere. ...