WASHINGTON — IT was to have been the ultimate defense: a network of lasers and other high-tech wizardry shielding the nation from atomic devastation.
Twelve years and $36 billion later, President Ronald Reagan's ''Star Wars'' dream of rendering nuclear missiles ''obsolete'' remains just that -- and public attention has waned.
But funding for ballistic-missile defense is shaping up as a laser-hot battle as Congress begins to hammer out the 1996 budget -- one of its central tasks over the next few months.
After the narrow defeat of a missile-defense bill in the Contract With America, the GOP's ''defense hawks'' are organizing a massive push to seek increased funds for programs that are developing smaller, more-limited systems with technology spawned by Mr. Reagan's original plan.
But the effort may be stymied by GOP ''budget hawks'' who plan to balance the budget in seven years by shearing $1.4 trillion in spending. Though Republicans have promised to spare defense spending from the budget ax, any increases will be a tough battle amid widespread cuts.
But supporters say increases of up to $1 billion are possible by cutting domestic programs and ''nontraditional'' defense items -- such as environmental cleanups.
Rep. W. Curtis Weldon (R) of Pennsylvania, a promoter of the antimissile effort, thinks the near-mythic proportions of Reagan's space-based plan led to public misunderstanding of the concept. ''Because Reagan promised all these things and did not have adequate controls and objectives,'' Mr. Weldon says, ''It allowed people to trivialize one of the most serious issues we face in the coming years'' -- missile proliferation.
The threat of nuclear attack from an unstable Russia, North Korea, or another emerging nuclear power remains real, military officials and GOP leaders say. ''We need to build a robust antimissile system,'' says Sen. Jon Kyl (R) of Arizona. ''It needs to be effective against the threats we will face in the next seven to 10 years.''
Arms-control advocates retort that the missile threat is overblown. And they say that unless ballistic missile defense (BMD) development is pursued delicately, the US will be seen by Russia as discarding the 1972 Anti-Ballistic Missile (ABM) Treaty.
That, these experts warn, could not only worsen already frosty US-Russian relations, but freeze nuclear disarmament and, in the worst case, fuel a new arms race. China has also expressed concern over the US policy.
The debate has left President Clinton in a dilemma. He wants to continue helping Russia reduce its nuclear arsenal and speed political reforms. But he also wants to avoid a bruising brawl with the GOP-controlled Congress that might give Republicans a chance to use the issue against him in the 1996 presidential elections.
The Clinton administration tried at first to please both sides, but now seems to be moving to beef up BMD development by reportedly proceeding with work on a naval antimissile system that many experts say could violate the ABM Treaty.
The domestic debate is driven in part by concerns over instability in Russia and the security of its nuclear missiles. ''Russia today is even more destabilized than it has ever been,'' says Weldon, the House Military Research and Development Subcommittee chairman. ''I question the whole command and control of the Russian nuclear force.''
The US military also fears that unfriendly states, such as North Korea, will develop or acquire missiles with long ranges.
The most common ballistic missiles are the so-called theater missiles, which have ranges of between 50 and 2,100 miles. About 13 countries have these weapons.
According to a Congressional Budget Office study, aside from NATO members, Russia, and China, only Israel and Saudi Arabia have missiles with ranges longer than about 500 miles. Several states, however, are developing such weapons, including India, North Korea, and Iran.
But arms-control specialists say many concerns about proliferation are too strong. ''No one is denying there is a threat,'' says Jack Mendelsohn of the Washington-based Arms Control Association. ''The argument is that the threat is being exaggerated and we are overdesigning against a limited threat.''
But current BMD efforts bear little resemblance to Reagan's plan, which envisioned an impenetrable shield of space- and land-based weaponry capable of zapping flocks of US-bound Soviet nuclear warheads.
During his tenure, President George Bush scaled back work on national missile defenses (NMD) -- designed to protect the entire US from missile attack. Instead, he put more resources into shorter-range theater missile defenses (TMD). These systems are used to protect US forces in the field or at sea, like the Patriot missile of Gulf war fame.
Clinton has taken the trend Mr. Bush set even farther. He has shrunk the NMD budget to $400 million and wants to spend more than $16 billion on TMD over the next five years. Officials cite the immediate dangers to US troops and installations from the proliferation of intermediate- and short-range missiles, such as the infamous Soviet-designed Scud.
Three ''core'' TMD programs are currently being developed for deployment between now and the end of the century: an upgraded Patriot, or PAC-3; the Navy's lower-tier system, in which a ship-launched rocket is mounted with a missile-killing projectile; and the Army's Theater High Altitude Air Defense (THAD), a small, more accurate replacement for the PAC-3.
The fiercest aspect of the current debate centers on the ABM Treaty, which bans the deployment of NMD systems but not theater systems. But the treaty does not specify when a TMD system becomes so powerful as to be used against strategic missiles -- thereby breaching the accord.
The Clinton administration's recent negotiations with the Russians -- which stalled last November -- have enraged NMD advocates. One condition agreed to would restrict development of the Navy's upper-tier interceptor -- a system that could one day be easily and cheaply upgraded into an ABM Treaty-busting NMD.
''There are scenarios where you could take upper tier ... and use it in an NMD capability,'' concedes Weldon. He admits that relations with Russia may be seriously affected by upper-tier development, but adds: ''We have to do what's in the best interests of our country and our people.''