Except for Lawrence Korb's position as assistant secretary of defense, I would not be inclined to respond to moot points in his June 9 op-ed article. [All-Volunteer Army: It Deserves a Fair Chance"]. But since he speaks for the department on a very important issue and states that both President Reagan and Secretary of Defense Caspar Weinberger share his "philosophical disposition against the governmental intrusion into private lives that conscription would involve," I feel obliged to reply.

His basic theme is that, depsite an eight-year redcord of unsatisfactory performance accumulated by three administrations, the all-volunteer force (AVF) is entitled to a "fair chance" to overcome past defects and demonstrate its right to extended life. To effect this turnaround, the administration proposes three remedies -- more pay, better training and renewed popular respect for the military profession.

I find such a program wholly inadequate to solve the problem at issue -- how to provide adequate trained manpower to permit the armed forces to carry out their functions in peace and to ensure their readiness for sustained combat overseas at the outbreak of war. The volunteer system has failed to produce manpower reaching these standards, and the administration's program would do little to remedy the defects primarily responsible for the failure.

These basic defects are twofold: 1) The low or marginal quality of many recruits and the fact that a disproportionate number of the recruits are poor, uneducated or black, and 2) the failure of volunteering to produce sufficient acceptable recruits to meet the needs of the reserve forces of the regular establishment. Of the remedies proposed to correct these defects, only the pay raise has direct applicability, because the other two -- improved training and restored prestige for the uniform -- whould be goals at all times, whether the men are volunteers or conscripts.

While a pay increase such as the 5.3 percent being considered is certainly due our enlisted men in any event, such an increase or any other likely to pass Congress will be too small to promise a substantial improvement in numbers, quality or ethnic balance of volunteers. We must bear in mind that during the decade ahead our recruiters will work against several adverse factors. In the first place, the armed forces will need more people than at present because of the force expansion resulting from the Reagan rearmament program. Also, demographic forecasts warn of a marked decrease in males of military age while administration economists predict better economic times, both conditions unfavorable to recruiting. Hence, I am very pessimistic as to the effectiveness of any program depending essentially upon a pay increase to solve the manpower problem.

My other reason for opposing a retention of the AVF is the urgency of our need for truly ready conventional forces in the turbulent time ahead. We have too many vital interests far from home in need of protection to tolerate forces unable to carry out their primary tasks -- to deter war or to wage it successfully if deterrence fails.

Korb is quite correct in saying that the AVF is "essentially a peacetime force," but not when he assumes that "in time of large-scale war conscription would be resumed and we should not have to rely on volunteers to fight the war." We could not get rid of the volunteer system so easily and painlessly.

We are paying a considerable price today for the AVF because of its limited contribution to the deterrent function in time of peace. There is little that is impressive about a military force with the visible manpower deficiencies that plague ours. Both friends and enemies abroad are aware of them and comment freely about their significance. NATO officers note the decline in professionalism of our Army units in joint maneuvers and exercises. The absence of a draft raises uncertainties about our ability to reinforce the alliance in time and gives political leaders occasion to question our reliability in a crisis.

The price we pay for the AVF would rise sharply upon the outbreak of hostilities. Contrary to Korb's assumption that in war we would not have to depend on volunteers, for several months after an outbreak of hostilities we would have only units of the AVF to man the defenses of Western Europe and Northeast Asia and to carry out overseas missions assigned to the Ready Deployment Force. If attacked by a formidable enemy, they would have to fight with no assurance of prompt reinforcement from the United States either in units or inloss replacements. In such a case, their plight would resemble that of the small British Army, rushed to France at the outbreak of World War I and destroyed there in a gallant effort to stem the German invasion. The British also did not believe in conscription.

Why is this wartime dependence on the AVF inevitable? It results from the very considerable time lag that is bound to occur between a decision to resume the draft and the emergence of the first conscript from training camp. Its length will depend on the time required for the passage of conscription legislation, for the Selective Service system to begin to function and for the armed forces to carry out the essential training. Without counting the time taken by Congress, which cannot be predicted, the delay in getting the first trained conscript is estimated at around four months -- a long time for the AVF to hold the fort unassisted.

To sum up, a further retention of the volunteer system to give it another chance would also mean further retention of mediocrity in military personnel and combat unreadiness in a large part of our forces. We cannot afford this indulgence any longer in this unstable world. We must return promptly to some form of conscription, modified in the light of Vietnam and postwar experience, which will produce armed forces with a blend of volunteers and conscripts, backed by adequate trained reserves to permit sustained combat. It would be a force roughly representative of all social classes, including a fair share of the best of our youth.

Eight years of AVF is more than enough.