Cap's first shoe

With Caspar Weinberger recommending an $8 billion cut in military spending for 1984, the administration has dropped its first shoe in the revision of the defense budget. No one is fooled that this is a substantive cut in military programs. Lower inflation rates and fuel prices as well as a holddown in military pay increases account for most of the reduction. In other words, Mr. Weinberger has simply revised his earlier budget estimate to take account of the good news on inflation. The actual budget will still call for a 14 percent increase in military spending.

However, considering that the Defense Department is resistant to any retreat from its massive military buildup, this at least is a first step toward taking a hard look at defense outlays with a view to reducing runaway budget deficits. There is a long way to go, but it can be hoped that the administration now recognizes it will have to make some compromises on arms for the sake of fiscal belt-tightening and economic growth.

The President argues, not unreasonably, that as a percentage of GNP the military budget is smaller today than it was in the Eisenhower and Kennedy years. That may be so. But the point is that since 1948 there has never been such a fast pace of growth in real defense spending as is currently planned. And this at a time when huge federal deficits could threaten economic recovery. Mr. Reagan's own economic advisers are concerned about the impact of letting the deficits grow to $300 billion and more by 1988.

The impact of the defense buildup itself also needs to be weighed. At present there is enough industrial capacity to produce for both military and civilian needs. But once the economy begins to expand, problems are forecast: delays in deliveries, upsetting defense timetables; price rises in some industries as the military and civilian sectors compete for resources; and some crowding out of private investment. In other words, the defense buildup takes place when the industrial base has eroded and therefore raises a question as to whether industry can meet the new demands without adverse effects.

This is not to call in question the administration's program for rejuvenating national defense. There clearly is a need to modernize the forces, especially in the conventional area. Before the Democrats left office in 1980, they, too, had called for a hefty rise in military spending (5 percent annually). But does Mr. Reagan's pace have to be even faster (7 percent or more)? Is there not a danger in approving weapons today which are of dubious need and which, by the time they are actually in production, cost far more than first estimated? (Two recent studies, including one by the Pentagon, warn that the cost of purchasing, maintaining, and operating the military arms considered for purchase under the current five-year plan will be much greater than the $1.6 trillion budgeted.)

It is thus not a matter of indiscriminately slashing away at the military budget, but of addressing it with the same tough-mindedness that has been applied to other budget categories. Selecting only weapons that are essential, choosing models that are less likely to lead to cost overruns, eliminating duplication and waste, taking care not to overload the civilian sector - this in the end should actually help strengthen defense.

In sum, it will take Mr. Reagan and Congress working together to analyze the military budget and to determine where cuts can be made without impairing security. The President at last seems prepared for some scaling back of the budget, stating that ''if it can be cut, it will be cut.'' That, along with Mr. Weinberger's slight give, suggests the administration is not set in concrete after all.