In his letter of Aug. 19, Joseph Mayer asserts that "most ignore the potential contributions to peace and stability that could be made by the deployment of strategic defenses." I don't think that most people ignore the peaceful contributions of the Strategic Defense Initiative. I just don't think such contributions exist.

A system that would make an adversary's weapons obsolete would by no means add to the stability of the present situation, mobile missiles or no mobile missiles. A simple model will help me prove my point. Take two gladiators of relatively equal strength, each possessing equal ability to kill the other. It is not likely that one will attack for he knows that his opponent could kill him instead.

On the other hand, if one is given a shield to block the other's attack, the situation is no longer stable. An attack mainly out of fear would then present itself as a possibility.

It is not a question of SDI as a means "of meeting the challenge of this new element {the 10-warhead SS-24} of the Soviet arsenal." There are much larger implications of a ballistic missile defense system. If one wishes to get rid of a particular threat, the answer can only be negotiations -- not tit-for-tat buildup.

Let us look away from kinetic-energy weapons, chemical lasers and ground-based interceptors and look ahead to a potential INF agreement, a possible START agreement and the strengthening of existing treaties such as SALT II and the ABM treaty.

TAYLOR KUNKLE Washington