Have tecnhology-drunk wishful thinkers forced the United States into buying overly elaborate weapons systems that won't work? In this article, Washington Post Pentagon correspondent George C. Wilson reports such allegations. William J. Perry, "Mr. Technology" at the Pentagon, taken the opposite side.

FOR THE PAST FOUR YEARS, William J. Perry has been Mr. Technology at the Pentagon. He was the undersecretary of defense who supervised the development and purchase of these wonder weapons that the critics are now faulting. In two lengthy interviews with The Washington Post, Perry, who has been retained by the Reagan administration temporarily as a consultant, defended the course he took. Here is what he said:

Q: Are the weapons the Pentagon is buying too complicated for the realities of battle?

A: Another way to put that question is: Wouldn't it be better, simpler, less complicated to go back to P51 airplanes [of World War Ii]? Go back to guns instead of missiles? The only trouble with that argument is that it overlooks the competition. If we could persuade the Soviets to go back with us, that wouldn't be a bad idea.

Unfortunately, Soviet tactical aircraft generally are more complex, more sophisticated than ours. The claim that they are simpler and more reliable is nonsense. People who make that claim are thinking about the Mig19 and Mig21. They are simple, reliable airplanes. But the Mig23 and Mig27 that the Soviets have built in the last decade are, in general, more complex, more expensive than comparable U.S. airplanes.

Our trend has been toward simplifying technological complexity. Their trend has been in exactly the opposite direction. We have changed roles. All of their modern tactical fighter airplanes are variable gometry wings [meaning they can be swept back along the fuelage for high-speed flight and extended straight out for takeoff and landing.] Now talk about something which makes an airplane complex and expensive -- that's it. That goes back to our F111 [TFX, built under former defense secretary Robert S. McNamara.] Their tactical airplanes are somewhat smaller versions of F111s, whereas we deliberately moved away from variable sweep wings on the F15, F16 and F18 to avoid that complexity.

Q: Air Force leaders have conceded that they overreached in setting down requirements for the F15's F100 engine. Isn't that a documented case of buying an overly complicated weapon?

A: I have mixed feelings about the F15. I think we overreached on the specifications for the engine when we designed it by pushing for that last 10 percent of performance. And we got it. But we paid a heavy price for it in terms of cost, reliability and maintainability of the engine. that's a problem we will fix and are fixing. I truly believe the Air Force's assertion that the F15 is the best fighter airplane in the world. Part of the reason for the F15's superiority, by no means the whole reason, is the performance of the engine.

Q: Do you think it's also a myth that Soviet tanks are simpler and more reliable than our tanks?

A: The Soviet T64, which is the high-technology Russian tank, is as complex as any tank we have built in terms of the gadgets that are on it: the night vision devices, the laser systems, the computer control firing systems. Also it has an automatic loading system, which ours does not. We still think our XM1 will outperform the T64 or any other Soviet tank.

If you really start to describe the complexity in weapons systems, and then you compare the current Soviet systems toe-to-toe with current U.S. systems, generally theirs are more complex.

Look what the Soviets are doing with their navy now. They built the largest, most complex cruiser in the world; they built the largest submarine in the world [the nuclear-powered Typhoon missile submarine]. They built the largest cruise missile submarine in the world, the Oscar. The U.S. Trident missile submarine is a simpler, cheaper system than the Typhoon. And certainly our 688 attack class submarines, which are capable of carrying as many cruise missiles as the Oscar, are simpler and cheaper.

Q: Haven't our new wonder weapons become too complicated for the ordinary soldier in the field to operate?

A: There is tremendous confusion on this point because people equate complexity with technology. A hand-operated calculator is a very, very sophisticated piece of technology. But if you compare the ease of operation and the ease of maintainability of that with the electromechanical desk calculators that were around five or 10 years ago, you realize that we've taken a giant step forward in simplicity.

The reason our equipment in the field today is hard to operate and hard to maintain is that most of it is 15 to 20 years old and loaded with electromechanical devices long past their useful life. They were never very easy to operate and maintain in the first place. But we're replacing that junk with new generations of weapons that are more reliable and much easier to operate and maintain.

If you compare the new XM1 tank with tanks we drove in World War II, you'll find it's much easier to drive the XM1. I could teach you to drive an XM1 tank and fire its gun in five minutes. And you would have a fair chance of hitting a moving target a mile away while you're moving with your first shot. You see a tank on a screen and then have to do two things: move a cursor [a dot of light] to put a little bull's eye on the target and pull the trigger twice. The first time the trigger sends out a laser beam to measure the distance to the enemy tank. A fraction of a second later you pull the second trigger and that shoots the gun. Between the time of pressing the first and second triggers the computer in the tank has decided how the gun should be pointed, and points it. And the computer is continuously sampling sensors to determine windage and tank motion. All this is happening in the computer. All you do is pull the two triggers.

I think the XM1 tank is the best in the world. It's superior to anything we've ever had and anything the Soviets have -- across the board in performance, reliability, ease of operation and maintenance. Tremendous emphasis was put during the design stage to provide reliability and ease of maintenance. One way you get this is by substituting microelectronice -- integrated circuits, for example -- for electromechanical devices.

I think the XM1 tank is better than the T64 ot T72. But our XM1s are still in our factories while their T72s are out in the field. It'll be a couple of years before we have enought XM1s deployed to make a difference. a

Q: How about strategic weaponary: Are Soviets intercontinental ballistic missiles [ICBMs] bigger but less complicated and more reliable than ours?

A: Soviet missiles today are not simple. They are still big, but they are no longer simple. The Soviet ICBMs are much bigger than their U.S. counterparts, and they are also liquid fueled instead of solid fueled. They are less efficient than their American counterparts. The new Soviet ICBMs, unlike the ones of the 1960s, have very complex guidance systems run by three independent computers.

As a consequence, the Soviet SS18 and SS19 ICBMs have accuracies comparable to U.S. ICBMs. That's a distinction between the ICBMs of the 1960s and the 1970s. So, while they have remained large and relatively inefficient in terms of nuclear yield per ton of missile, they are no longer simple and they are no longer inaccurate.

Q: If we are indeed more efficient, getting more bang for the buck, why are there so many alarms coming from the Pentagon about new Soviet weapons?

A: As I'm all too agonizingly aware, from the time you actually spend research and development money until the time the money is converted to deployed military capability is a good many years. Therefore, the fact that the Soviets have been ahead of us in defense research and development spending for a decade doesn't give them an instant capability. But we are beginning to see now the fruits of that extra spending. Things which 10 years ago we could sit back and say, "Well, we're comfortably ahead of them": ICBM guidance; look-down-shoot-down missiles and radars; submarine detection systems -- we could tick off these great advantages we had over the Soviets which made a whale of a difference. These advantages allowed us to say the large size of the Soviet systems is not a matter of great concern.

Now the cumulative effect of the Soviet's spending more for the last 10 years on military research and development than the United States is beginning to be felt, beginning to be observed in deployed systems. We now see a deployed Soviet ICBM with guidance comparable to our guidance; we now see look-down-shoot-down missile and radar in the final test stage, which we expect to be deployed soon, which in some ways is comparable to the capability we have.

So, to a certain extent, the difference is that they were behind, and it has taken them a while to catch up. There is another fundamental difference, though, which is going to be true on into the 1980s. That is that their research and development program is less efficient than ours, fundamentally because they don't have the high technology commercial industry to base it on.

Our great advantage in defense is in microelectronics, microcomputers, which have been based on the advances conceived, sponsored and paid for by commercial research and development to a very considerable extent. The Soviets don't have anything comparable. So, simply comparing U.S. and Soviet military research and development budgets does not tell the whole story.