Need soldiers? Why not use the reserves? Here's why

As pressures increase for reduction of the defense budget, Congress has begun to turn toward a tried, if not always proven, escape hatch - the National Guard and Reserve.

Rather than accede to an administration request for increased active military strength, armed services committees of both the House and Senate have acted to increase reserve strength by 12,000, with attendant advice that the services transfer functions from the active to the reserve category.

Rep. Les Aspin, chairman of the House Armed Services Subcommittee on Military Personnel and Compensation, is planning hearings this summer to examine the possibilities for further shifts from the active to reserve rolls.

The last time this sort of thing occurred was in the early 1970s when a decision was made to abandon the draft and depend on volunteers, shifting to the Guard and Reserve functions that could not be supported by the diminished active manpower pool.

The decision having been made to make the shift, studies were ordered to see if it could be made to work.

Those studies, principal among them the Army Study of the Guard and Reserve Forces, June 1972, are still the best information available as to what the Guard and Reserve can and cannot do. This is because they were conducted when Guard and Reserve units were at the highest levels of support and performance in their peacetime history. Turbulence induced by the change to volunteer recruitment has made it impossible to regain that level of performance in the years since.

The notion that active military functions could be transferred to Guard and Reserve units was born in the success of the Air National Guard and Air Force Reserve. These had been built from a ''flying club' status in 1949-50 to units that could match and often exceed Regular Air Force performance in certain roles and certain circumstances. The early 1970s studies, however, lit some warning lights:

* Much of the efficiency of the Air Guard and Reserve is the work of people with matching or near matching civilian skills; for example, airline pilots. No one knows to this day what would be the impact of taking them from civilian jobs that conceivably might be of greater importance in an emergency than their military jobs.

* The Air Reserve forces are manned often at well over 20 percent by full-time, long-service ''technicians.''

* Most important of all, it has proven easier (if much more expensive) to ''man the equipment'' in Air Force parlance than to attain the close teamwork required of large numbers of people in the Army combat units.

In general the early 1970s studies found that, while certain specialized support units can be ready for almost immediate use in an emergency, the vast majority of combat units could not be expected to be ready to fight a first-class enemy until about 90 days after mobilization, for the smaller units, and up to six months to a year for the larger units.

Any attempt, therefore, to ''solve'' the present budgetary dilemma by shifting a substantial share of the rapid deployment requirement to National Guard and Reserve combat units will encounter grave strategic problems. Indeed the process and the problems have already begun since several US-based active Army divisions cannot deploy at full strength without their Guard and Reserve combat components. Those Guard and Reserve units well may be reported ''ready'' or nearly ready by ''pencil work,'' their deficiencies hidden by the Army's refusal to adopt the sort of operational readiness inspection by which the Air Force verifies the status of its Guard and Reserve units. That could lead to a large political backfire when it becomes apparent, in combat, that Congress not only permitted but encouraged the deployment of units that had no business anywhere near the front line.

Try as they might, neither the administration nor Congress can continue to avoid for much longer the fact that we are in a grave strategic crisis. The Guard and Reserve have a valid role to play, but not as Band-Aids to a national failure to face up to the fact that the US is committed beyond the scope of its economic resources and military capacity.