The debate on the Reagan defense program seems certain to heat up during the coming year. Whether it will also shed light on the critical issues involved remains to be seen. That will depend on how far the several different strands of criticism can be separated out and analyzed on their merits.
The need to increase defense spending to counter the steady Soviet buildup was already recognized in Mr. Carter's last budget. In his military budgets, Mr. Reagan has raised the amounts both for current spending and for future commitments. In large part, they provide for more of the same items or revive weapons cancelled by Mr. Carter, like the B-1 bomber.
In the context of Mr. Reagan's total fiscal program, the higher defense budget inevitably raises the issue of ''guns vs. butter.'' Given his substantial tax cuts, it puts pressure on funding for social programs, especially for low-income groups, and adds to the large projected deficit. Those concerned by these effects focus mainly on the total amount devoted to defense, without much regard for specific items. Some on the defense side take an equally global approach insisting that annual increases of 7 percent or some other figure are essential - without many supporting specifics. That tends to encourage the services to buy more on their ''wish lists.'' Of course, the United States must spend what is needed for its security, but the question is what is needed. (And that should be the question for social programs, even if that means delaying the tax cut.)
Thus many critics, although favoring higher defense spending, are concerned about the specifics of the proposed program. Of these, some argue that the military services tend to be infatuated with high technology and to design expensive weapons which are too complex and unreliable to work well in combat. They cite some of the most advanced planes or the M-1 tank, which requires an accompanying bulldozer, and frequent repair, and guzzles fuel. In the drive for the ''state of the art,'' the cost and complexity of specific weapons outrun their performance in practice. The criticism appears to have merit, at least in some cases. But striking a proper balance will involve resisting defense contractors promoting advanced technology and designers intrigued by novelty. It may require giving a greater voice in the choice of weapons to the ultimate users.
The third and most basic criticism questions the premises of the program. It is being made by eminent retired military leaders like Gen. Maxwell Taylor, by members of the Congress like Sen. Gary Hart, and many outside experts. Essentially, it is that the military program is more the product of bureaucratic rivalry and momentum than of solid strategic analysis. These critics stress that the strategic environment has been radically changed by nuclear parity, the wider reach of Soviet power, the vulnerability in the Middle East and of the sea lanes. Fresh strategic thinking is essential to define the tasks of the armed forces in the next two decades, to fix priorities, and only then to choose appropriate weapons systems. The lack of such strategic planning is the most serious deficiency of the Pentagon.
Last week this critique received strong support in an article entitled ''Why the Joint Chiefs of Staff Must Change,'' by their present chairman. His central point is that the present structure of the JCS inhibits objective analysis of strategy and missions. All members except the chairman are also heads of the Army, Navy, Air Force or Marines. As General Jones says, the traditions of a service and loyalty to it make it ''quite difficult to assess changes in its environment with a high degree of objectivity. . . . Since fresh approaches to strategy tend to threaten (a service's) interests and self-image, it is often more comfortable to look to the past than to seek new ways to meet the challenges of the future.'' That tendency, plus the service rivalry for resources, ''can lead to a preoccupation with weapon systems, techniques, and tactics at the expense of sound strategic planning.''
As a remedy, General Jones proposes enhancing the authority of the chairman, limiting service involvement in the JCS process, and improving the training and rewards for joint duty in order to overcome parochial biases. These changes should be useful but many do not go far enough.
Yet getting them adopted will be extremely difficult, as past experience has shown. It will have to overcome dogged opposition from the services and the protectors of service autonomy. Congress should help in pushing through the necessary reforms; but to do so, the relevant committees will have to shift their attention from details to strategic issues. The fact that a group in the Congress is attempting to foster such changes is a hopeful sign. The administration should follow through on the effort to clarify our strategy and on the reforms suggested by General Jones.