`Star Wars': New Name, Old Challenges

THE Strategic Defense Initiative (SDI) is no more. But its successor, the Ballistic Missile Defense Organization, bears a striking resemblance to what SDI had become.

In announcing a reorganization of the program long nicknamed "Star Wars" last week, Secretary of Defense Les Aspin has simply recognized reality. In recent years President Reagan's dream of a defense against long-range missiles had been replaced by a more pragmatic Pentagon vision: Work on defense against tactical missiles, such as Saddam Hussein's Scuds.

A system capable of defending the US against long-range missiles was, and is, still a goal of SDI/BMDO work. Secretary Aspin says his best estimate is that the US has 10 years until some rogue nation is able to acquire both nuclear weapons and long-range missiles capable of hitting the continental US.

But the exotic laser and particle-beam weapons promoted by exuberant scientists in SDI's early years have proved something of a dream. They won't be ready until decades into the 21st century, if at all.

Thus the most significant actual change in Secretary Aspin's announcement was bureaucratic.