The news story "Ethical Questions Arise From Gulf Strategy" {front page, Sept. 23} by E. J. Dionne Jr. properly raises important ethical issues. Unfortunately, Mr. Dionne's discussion of "just wars" omits the central premise of U.S. and world thinking about ethics in war.

As a lawyer and a retired Marine Corps Reserve colonel who instructed U.S. armed forces in the law of war, I know that historically the concept of the "just war" has been used as a justification for outrages of conduct in the course of war. Essentially the just war conceit is that if a nation's cause is "just" its conduct need not be. Not surprisingly, each nation decided its own wars were "just."

Today all treaties and international law demand certain levels of conduct, regardless of a nation's claim of justness. In short, international law does not differentiate between the "just" and "unjust" participants in war. Rather it governs how the war is fought. The law of war is embodied in the Hague Conventions of 1907, the Geneva Conventions of 1949 and numerous other treaties, all of which govern conduct in war. Rights and obligations under the law of war do not depend upon which party stands on the higher moral ground.

I have no doubt of the "justness" of the United Nations' response to Iraq's attempted annexation of Kuwait. What must be kept in mind, however, is that any moral conclusion that we are engaged in just war is irrelevant to our obligations to comply with the law of war. Our military forces, and those of Iraq, must conduct themselves in accordance with the law of war.

I believe the U.N. forces will; I know the U.S. Marines will. If Saddam Hussein and the Iraqi military do not, the law of war provides for trials for war crimes. By holding ourselves and our enemy to the standards of the law of war, we will be holding the moral, ethical and legal high ground. DONALD H. GREEN Washington