NEW YORK, JAN. 21 -- After years of weathering flak about cost overruns, bribery schemes and gold-plated gadgetry that doesn't work, the U.S. defense industry finally has something to crow about.

For the past six days, America has huddled around its TV set watching the videotaped replays of U.S. weapons splitting the middle of an elevator shaft in Baghdad, shooting missiles out of the night sky over Dhahran and blowing out targets hundreds of miles away with pinpoint accuracy.

"It's certainly a vindication of the high-technology approach," said Byron K. Callan, a vice president and defense electronics industry analyst at Prudential-Bache Securities Inc. here. "You spend a lot of money on this stuff, but you save a lot of lives as well."

Phillip Giaramita, vice president at Bethesda-based Martin Marietta Corp., spoke for the industry today when he proclaimed, "The Persian Gulf experience shows the value of using sophisticated, high-tech systems and that the U.S. is likely to require more of these systems in the future because they are versatile, mobile and can operate in many different environments."

Wall Street has reflected the general euphoria. In what analysts described as a largely emotional reaction to the war footage, stocks rose briskly again today for such big defense contractors as Raytheon Co., Lockheed Corp., Martin Marietta Corp. and McDonnell Douglas Corp. General Dynamics Corp. shares have soared 37 percent since the fighting began.

An index of aerospace and defense stocks, compiled by Dow Jones, today rose about 2.3 percent. At the same time, the blue chips in the Dow Jones industrial average fell 0.7 percent.

At companies such as Martin Marietta, the expectation is that the visible success of the Patriot missiles and other high-tech weapons will prompt the Pentagon to want more such sophisticated systems for its future force structure.

But industry analysts warn against going out and buying defense industry stocks just because you see some amazing video on the evening news.

For starters, any boost in sales sparked by success in a short gulf war is unlikely to make up for business already lost because of the Cold War's end, according to many analysts.

"There's no major threat out there to replace the one that has dissipated, which is the Soviet Union. I still expect defense spending to decline over the next few years," said George D. Shapiro, a director and aerospace analyst at Salomon Brothers Inc. here.

Peter L. Aseritis, a former Marine captain who now is a defense electronics analyst at First Boston Corp. here, said, "Once we get the war out of the way, which I expect to take between three and six weeks, the defense budget will continue to be cut."

Furthermore, even if the Persian Gulf War results in a flurry of initial orders for some high-tech weapons by the United States and other governments, the crushing of Iraq's military machine could result in reduced arms sales, particularly among formerly big-spending customers in the Middle East, analysts warned.

"A neutered Iraq, or whatever is left of Iraq, is going to mean elimination of a major strategic threat to U.S. interests in the Middle East ... and new reasons for the Israelis to reduce their long-term defense needs," said Callan of Pru-Bache. "In terms of looking for brand-new markets for these {defense} companies to conquer, I'm a little leery."

As war clouds gathered over the Middle East, Saudi Arabia was said to be considering an order of between 20 to 25 more Patriot missile batteries, for example, at a cost of $165 million to $200 million apiece. The Patriot's worth has now been demonstrated vividly to the Saudis in the skies over Riyadh and Dhahran. But at the same time, if Iraq is defeated, the Saudis might well consider cutting their order for lack of a worthy foe.

"Certainly, the Patriot missile might be more in demand abroad than it was before," said Aseritis. "But, on the other hand, if there's no more Iraqi threat in the Middle East, the Saudis won't need 25 more batteries."

Lawrence Korb, a senior fellow at the Brookings Institution in Washington and a former assistant secretary of defense, added that while the recent success of high-tech weapons will have foreign governments lining up to buy them, the U.S. government may be reluctant to approve the sales if they reignite an arms race in unstable regions such as the Middle East.

"I think there will be some concerns about the spread of technology," Korb told United Press International today. "You've got to be very careful about letting that technology out because today's friend is tomorrow's enemy. And you wouldn't want that thing hurled up there at American planes."

Another damper on several defense stocks is that many of the companies are so large that the success of one product is not enough to make much difference for the bottom line.

For instance, although the Pentagon said it was ecstatic about the performance of the Tomahawk cruise missile, that weapon accounts for only a fraction of the revenue of manufacturers General Dynamics and McDonnell Douglas. As a result, even if demand for the Tomahawk soars, the increased sales will not make up for planned or possible cutbacks by the Air Force in deployment of costlier jet warplanes, which represent a much bigger chunk of business for both companies.

Also, McDonnell Douglas, builder of the commercial Delta rocket, said today it would lay off 300 workers nationwide because of a dwindling need for commercial rockets and stiffer foreign competition.

Nevertheless, there's little question that the defense industry is bound to reap some economic benefit just from the current turnaround in its image. While it is likely that there will be some highly publicized instances of weapons' failures before the war is over, analysts said, it seems for the moment that Congress and the public will be more willing to spend money on high-technology products after witnessing the initial successes.

"I think the main impact has been an industry going from being very much disliked, and seen as having ripped off the American taxpayer, to being one that the American public believes is doing a pretty good job," Shapiro of Salomon Brothers said.

Today, that perception boosted the stocks of Loral Corp. and E-Systems, two major defense electronics companies with products being used in the thick of the Persian Gulf War. New York-based Loral makes electronic defense systems for U.S. warplanes, which act like "fuzz-busters" against enemy radar. It also makes the laser-targeting technology featured on some of the sensational video shots of bombs being directed directly into Iraqi installations.

E-Systems, based in Dallas, builds and operates electronic intelligence gathering systems used by spy planes and spy satellites -- which have been employed to select the targets hit by U.S. missiles and bombs.

One small company whose stock rose $2.12 1/2 to $14.37 1/2 today on the war news was Alliant Techsystems, based in Minneapolis. Alliant makes cluster bombs and other ordnance being dropped on the Iraqis.

In the Washington area, a number of defense firms have already basked in the glory of Persian Gulf success -- and watched their stock climb about 10 percent. Martin Marietta, in addition to performing 30 percent of the work on the Patriot, also makes the nighttime navigation and targeting system for the Air Force's F-15E and F-16 fighters -- that, in 1990, gave the company $200 million in revenue. A similar system used in the Army's Apache helicopter generated $150 million in revenue for Martin Marietta.

The company also had a hand in developing the launching system for the Navy's Tomahawk missiles -- a program worth $100 million a year to Martin Marietta.

Meanwhile, at Radiation Systems in Sterling, Va., employees are working overtime to supply U.S. forces in the Persian Gulf with military communications equipment, according to Chairman Richard E. Thomas. The company's antenna systems are used by the military to communicate with each other through satellites.

Radiation Systems had about $14 million to $15 million in military contracts that, without a war, would have been spread over 18 months. Now the timetables have been moved up and the work will be completed in six to eight months. As a result, Thomas said he expects to increase the company's work force by 20 percent.

At Survival Technology Inc., a medical devices company in Bethesda, the company has booked almost $20 million in orders from the government for its antidotes for poison gas. The injector systems, to be used after a nerve gas attack, have been issued to U.S. troops serving in the Persian Gulf. The company stock soared in September after news reports of the initial orders, but has fallen back since the fighting began.

If and when the United States and its allies mount a ground offensive to expel Iraqi forces from Kuwait, several companies' stocks may be affected by the performance of weapons that have had controversial pasts, analysts said.Analysts would watch to see whether McDonnell Douglas's Apache antitank helicopter and General Dynamics's M1 tank function well in the desert. There has been speculation that sand would clog some of their moving parts and make them ineffective.

LTV Corp.'s Multi-Launch Rocket System, or MLRS, an armored, tracked vehicle that fires missiles containing tank-seeking bombs, also will get its first full-fledged combat test.

Prudential-Bache's analyst Callan said he will be looking to see whether EDO Corp.'s helicopter-towed mine-sweeping system was effective against Iraq's arsenal of floating mines, which are likely to be deployed against U.S. naval vessels supporting a ground assault in Kuwait.

Staff writer Stan Hinden contributed to this report from Washington.