In his analysis of the ethics of Lt. Col. Oliver North and Adm. John Poindexter {op-ed, Aug. 15}, Samuel Ginder conveniently ignored an "obligation" that was incumbent upon the two National Security Council staffers -- that of acting according to the laws of the United States.

In doing so, Mr. Ginder created a false picture of what really was the moral dilemma facing the two. He said the dilemma was in choosing among equal alternatives -- "truth, loyalty (to the president) and honoring an obligation (to the contras)" -- when in fact it was not this at all.

Col. North and Adm. Poindexter were sworn to uphold the law, and they chose to break or circumvent it. That they lied in thus breaking their obligation to the one thing in this country that is greater than any president or any military movement only compounds their transgression.

Mr. Ginder obviously has an "agenda" of his own in taking Colman McCarthy to task. Unfortunately, that agenda belies as obtuse a view of constitutional government as that through which Col. North and Adm. Poindexter saw their mission.

For Aristotle and the ancient Greeks, the situation and, "most important, the motivation, or what lies in the heart" may have been enough to justify almost anything, as Ginder said. But sincerity alone offers no sanctuary in the United States for those who ignore our laws.

When are conservatives like Mr. Ginder ever going to realize that?

ALLAN L'ETOILE

Sterling