Approaches vary -- and confound.

Last March, the Administration proposed outlays of $188.2 billion for defense in 1982 -- an increase of $26.7 billion over 1981 spending. Last fall, however, the Administration proposed to reduce its own request by $2 billion in an effort to trim the deficit for this year. Now, the Administration is preparing a defense budget for 1983. The President is expected to ask for a 15 percent hike -- a 7 percent increase after subtracting for inflation.

A recent Pentagon study shows the Reagan plan requiring another $750 billion in defense spending over the next five years, atop the $1.5 trillion already projected by the Joint Chiefs of Staff.

Everyone in Congress recognizes the need for a stronger defense. So does the public, according to opinion polls. But reality is not always a handmaiden to the wish. On the one hand, people want more defense spending. On the other, they want lower taxes and a smaller federal deficit. It is left to Congress to somehow reconcile this whipsaw of public opinion. And there is another piece to the puzzle -- something I call the "backyard syndrome." While everyone may recognize the need for a given weapon or military base, no one wants it in their backyard.

At the outset of World War II, it was difficult to find Americans who quarreled about the location of air bases, army posts, submarine ports, ammunition dumps or just about anything that had to do with the war effort. There was a "clear and present danger," and a unified country didn't quibble. If the government decided to build some sort of installation near a city, folks said that was fine, because we've got to win this war and let's do whatever it takes. That was that.

That kind of mobilization was not without domestic risk, and even accidents. As the Air Corps worked around the clock to turn out new pilots, there were crashes. Most were kept away from population centers, but a few were not. There were accidents at ammunition depots, aboard munitions trains, in defense plants. But in the face of a common threat, there was unity of purpose. What had to be done, had to be done.

Americans today seem at cross-currents with themselves.

When Davis-Monthan Air Force Base began operating, it was considered far from the City of Tucson and nobody seemed to mind much what went on "out there." As the years passed and local officials okayed plan after plan that allowed homes to be built virtually right up to the air base fence, there came a sudden cry: "What's this air base doing in the middle of a big city, anyway?"

We've had a long, agonizing debate in Southern Arizona about military overflights of Tucson and a few smaller communities. The debate reached a crescendo following the tragic crash of a jet fighter near the University of Arizona in 1978. Trying to work out new air traffic patterns acceptable to all parties has been one of the thorniest problems I've faced in years.

I would venture a guess that a good many hard-working, conscientious folks who would agree that we need a strong national defense, might also tell me in no uncertain terms that they want no Air Force jets flying low over their homes. The air base is fine, they might say, but can't we put it somewhere else?

We see another developing concern involving the MX

In the decade or so that followed, the march of immigrants that has swollen Tucson has moved, slowly, closer and closer to the Titan silos. Last fall, when the Reagan Administration proposed to replace the Titans with the MX, the volume of complaints was heavy. My mail, in fact, ran 2 to 1 against placing the MX in the Titan sites. It's a familiar story: we're all in favor of a strong national defense, but we don't want the MX in our backyard. Put it somewhere else.

In this instance, the Administration solved the problem for us. The deployment of the initial 40 MX missiles will not, in all likelihood, be placed in the Titan silos near Tucson. But if we want the MX, it has to go somewhere.

There are probably dozens of similar examples throughout the country, and there are new ones born every year. On the one hand, we see people adamant and determined that we launch a defense build-up, and on the other, that virtually nothing be built or based near where they live.

Most of these concerns are heartfelt, sincere and honest. No one wants to live with the possibility of an airplane coming through the roof or pieces of a missile landing in the front yard (as happened when a Titan silo exploded last year in Arkansas).

But the push for new defense spending and the reluctance to accept military hardware as a neighbor does tie us in a knot. We can't very well build new weapons systems if no one wants them nearby, for they must be near something.

It's a bit reminescent of the story about the man who had his coat stolen in a restaurant. As a policeman drew his gun and gave chase, the man yelled, "Shoot him in the pants!"

All of us may have legitimate doubts about a given weapon deployment scheme. I opposed the multiple-point basing setup for the MX that would have imposed a nuclear racetrack on Nevada and Utah. I did so, however, on the basis of national security considerations as well as my regional interest in the Southwest. In the case of Southern Arizona, we already had the Titans. Secondly, I believed then and believe now that the MX would be more effective aboard submarines than based on land.

Difficult as it may be, there are times when the national interest requires that something or other be in our "backyard." We should work to minimize human inconvenience or danger, and on closer examination, we might even find other, more appropriate sites. But we have to be prepared to accept the fact that a sound balancing of interests may require nearby placement of a weapon or a base.

"Spending more for defense" can't mean much until we get down to what it is we are spending for. No member of a family would say, "Let's spend more on ourselves next year," without getting into a rather detailed discussion of exactly what it was they thought they needed, could use, wanted -- and could afford. Likewise, increasing the defense budget is meaningless unless we take a careful look at what it is we need -- and determine what we can afford.

My friend and colleague in the Senate, Gary Hart of Colorado, put it well when he said. "Indiscriminate calls for more defense spending make no more sense than indiscriminate efforts to cut military budgets. We must stop

It is possible, in fact, to spend a great deal more money and actually end up weakening a country's defenses -- France proved it could be done when it built the Maginot Line, at a cost of billions of francs. But the Maginot Line was worthless against Hitler's Blitzkreig.

England poured 60 million pounds into the defense of Singapore. But all the guns faced the sea and when the city was attacked by land, it was easily overpowered.

In another time, the grand strategy of any great nation was simple: if you were powerful, you could take the less powerful nation, occupy its cities and end a war quickly. Those days are gone.

The world no longer is in such a clear balance. At the end of WW II, the United States alone possessed the atomic bomb. That single weapon made us the most powerful country in the world and our supremacy was unquestioned.

Since those days, at least 6 countries, large and small, have come to possess their own nuclear weapons, and more are working to build their own bombs. Before the end of this century, as many as 25 different countries can be expected to boast of having nuclear warheads in their arsenals.

While we must be ready for the threat of a showdown with the Soviet Union and be ready to back up our own resolve, we must be better prepared to meet Soviet-inspired adventures that always involved "troops by proxy."

In these engagements, the Soviet-backed forces have achieved a high degree of skill in the development of "maneuver warfare" -- conducting fast-paced wars of attrition aimed more at interrupting an enemy's cohesiveness rather than facing off on a battlefield and trying to defeat him by inflicting the greater losses.

These engagements shouldn't be confused with the abilities or shortcomings of Soviet forces. While strong in some ways, they also have their own shortcomings. Where Russian troops have become directly involved in a conflict, they have not fared well. In the encounter in Afghanistan, the Russians have been bogged down for months, their army hampered as much by unwieldly bureaucracy as by commanders who are employing the strategies of another age. There exists now a critical drain of young men in the Soviet Union to the military, that threatens to cut into the workforce needed to keep the factories running.

Judging from the kind of conflict the Soviet Union likes best, it seems to me that the first thing we have to do is be prepared to meet maneuverability with maneuverability. That's why I question the wisdom of pouring billions of dollars solely into exotic weapons systems like the Trident submarine or the M-1 tank or the B-1 bomber.

In the case of the Trident, we have one vastly powerful and expensive submarine which can be reduced to ineffectiveness by one inexpensive missile. Why not spend that money on several, cheaper and more conventional submarines? We pull all our eggs out of one basket, we increase our maneuverability, we increase our firepower and we get a better buy for the same number of dollars.

In the case of the M-1 tank, we now have a weapon that is so heavy (60 tons) that we lack a cargo aircraft capable of airlifting it. Meanwhile, the Russians have concentrated on developing new, light tanks -- less sophisticated, but cheaper and easier and faster to manufacture.

The Marine Corps, meanwhile, has adopted the Harrier, an aircraft capable of vertical takeoffs and landings. The A-10 "tank killer" aircraft, used by the Air Force, is a good military buy. The Surface Effect Ship (hovercraft) is yet another good example of the kinds of weapons that fit our kind of age. So is the Rapid Deployment Force.

The Air Force needs a simpler fighter. All branches of the service need to reexamine policies and traditions on officer education and career opportunities. We need to take a second look at unit cohesion, force structure and the nature of assignments.

Our emphasis, however, must not be centered on procurement. Yes, we must develop a more cost-effective procurement policy -- financial and strategic considerations require it. But we must define more clearly the military missions that our defense spending is expected to respond to. We must seek greater commitment from Japan and Western Europe to our mutual security needs. We must improve the forward positioning of our supplies and the readiness of our forces. We must enhance the quality of our volunteer army.

And we must pursue arms limitations agreements for both strategic and conventional forces. The current arms race is not in the interest of the United States or the Soviet Union.

We have a mutual interest in limiting nuclear arsenals and reducing troop levels in Euorpe. Such negotiations must protect our national interests, but they must go forward. If successful, negotiations can go a long way toward cutting the defense expenditures outlined by the Administration, and relieving in part the enormous burden we bear.

Until that happens, however, the whole discussion is not about more or less for defense, but about selective spending -- let's get the most for our dollars, the most effective, capable, efficient and the toughest military machine we can buy, at the best price, to meet the situations that we will face in the 21st Century.

An article written by Edward N. Luttwak discussing the state of the American military makes a first-rate point: in lieu of an operational art of war, Luttwak says, we have attempted to find high-technology solutions for every problem of war.

He's right.

The United States must redirect its defense efforts -- in a way that takes public sentiment into account, and in a way that addresses not only the security of the country, but the type of conflicts we have faced since the end of the last world war.

A computerized version of the Maginot Line just won't see us through.