Washington — Compared with what's coming, current intramural squabbling over next year's defense budget may be small potatoes. Looming even larger is a more fundamental fight over managing the Defense Department.
With five-year spending plans approaching $2 trillion and annual military purchases exceeding $160 billion, the stakes are enormous - much greater than the likely cut of $10 billion to $15 billion being discussed for the Pentagon's 1986 request.
Recent complaints over spare parts, warranties, competitive pricing, faulty weapons, and US military performance in Grenada are symptomatic of deeper problems.
According to many congressional and private experts, Defense Department civilians, and uniformed officers, the planning and budgeting system needs major overhaul of the kind former Secretary of Defense Robert McNamara tried to impose 20 years ago, with only limited success.
''There's a broad perception throughout the country that DOD isn't working very well,'' says Philip Odeen, who directed programs analysis for the National Security Council and now heads a study group on defense organization at Georgetown University's Center for Strategic and International Studies.
''The time has come to look very hard at organization,'' he says.
Defense Department officials acknowledge that the growing perception of mismanagement has helped reduce public support for the Reagan administration's military buildup.
''Everybody can understand the price of spare parts,'' says Assistant Defense Secretary Lawrence Korb, who also agrees that ''there are longstanding problems with very deep historical roots.''
That same concern is found among the officer corps, where logistics and weapons reliability can be a matter of life and death.
Marine Corps Reserve Maj. Mark F. Cancian writes in a recent article in Naval Institute Proceedings: ''Two decades of chronic cost overruns, strategy/resource mismatches, and declining force structure have forced military leaders to ask: Are we managing for defeat?''
In a New York Times op-ed column, Lt. Col. David Evans, an active-duty marine who works at the Pentagon, described a ''runaway system'' where $400 claw hammers are ''symptomatic of how major items like bombers and cruisers themselves are priced.''
As it has in recent years, the Pentagon is likely to continue resisting legislated reform.
Defense Secretary Caspar W. Weinberger and other senior defense officials argue that recent management reforms they have begun will lead to more efficient procurement. ''In defense, there are no short-term fixes,'' Mr. Korb told an American Enterprise Institute forum this week.
The White House Office of Management and Budget has formed an interagency group on defense management.
It was reported this week that a newly created position of deputy assistant defense secretary for spare parts program management is to be announced shortly.
But the pressure for structural change and reorganization that has been growing for about two years in Congress and elsewhere will be hard to resist.
Earlier this year, the Republican-controlled Senate named a Task Force on Selected Defense Procurement Matters. Sen. Dan Quayle (R) of Indiana is urging better congressional oversight and a two-year Pentagon budget to enhance stability in military spending.
''This reform would have obvious benefit,'' Senator Quayle told the National Security Industrial Association recently. ''It would introduce greater stability into weapons-system procurement. It would permit the Armed Services Committees to spend only every other year working on defense budget issues, and to use the alternate years to conduct broader oversight. It would also permit senators to broaden their knowledge of defense and national-security issues as a result of having time in alternate years to consider questions that go beyond line-item authorizations.''
Congress is also likely to continue pushing for reform of the Joint Chiefs of Staff (JCS). Legislation in this area has been approved by the House in the past two years, but has faltered in the Senate.
Critics say that because each JCS member also heads his own branch of the service, interservice rivalry overshadows the broad and effective advice on military matters that civilian leaders need. Former JCS members and others have said that the role of the JCS chairman needs to be strengthened, the joint staff expanded, and assignment of officers to cross-service posts given greater status.
''Reform of the JCS is long overdue,'' says former US Comptroller General Elmer Staats. ''The basic question of divided loyalty remains. The Pentagon has not developed the services into a unified, mission-oriented fighting group. The services sometimes seem to design weapons systems as if they're going to fight separate wars.''
Philip Odeen says Pentagon officials and lawmakers both need to spend more time thinking about what programs and weapons the country really needs for an adequate defense and less time tinkering with military spending for political reasons.
''The budget process needs to be revamped significantly,'' he says. ''We've got to be much more tough-minded up front about what we buy.''
In the early 1960s, Robert McNamara initiated a ''planning, programming, and budgeting system.'' He said it would be ''a mechanisim for developing a realistic program for meeting both our current and long-range military requirements.''
It now appears that others will try again to meet the same goal. Says Melvin Laird, another former US defense secretary, ''This whole area of defense planning is going to occupy a major portion of this coming Congress.''