Every so often a reader writes an urgent personal appeal in such disturbing language that it cannot be set aside. I have such a letter before me now.

The writer describes himself as a "middle-of-the-road retired Foreign Service officer," and says he identifies with nearly everything I write.

His concern, nevertheless, rests with my failings as a columnist and commentator. "Not with anything you've written," as he says, "but rather with things you haven't."

He means: "Why hasn't your voice been heard on the Middle East?"

Specifically heard, that is, about what he calls "the little holocaust going on in Lebanon in which American arms are being used to keep the slaughter going, not to stop it as in World War II."

He goes on to say:

"I suggest if you wait much longer, for the rest of your life when you look in the mirror you will know that perhaps the only time in your life that you really had a chance to speak out against mass murder before it occurred, you didn't."

After a lengthy, impassioned, eloquent statement along those lines, he concludes:

"As always, there are two sides. You can be for the slaughter of Arab civilians with American weapons in order to get the PLO members who are sheltering among those civilians, or you can be against it. To abstain is to acquiesce. For the sake of the rest of your life, I hope it isn't too late when you make your choice and break your silence to write about it." Dear Sir:

You flatter me when you suggest I can add anything to the present debate about the continuing struggle between Jews and Palestinians in the Middle East. I am not an expert on that region. And determining the accuracy of what has been occurring there, specifically the extent of civilian casualties, remains difficult from this distance. Even if one knew all the "truth" in this most frustrating of historical conflicts, it still would not clear the way to where certain justice lies. When I say that, I do not mean to use my lack of expertise and precise information as false shields to avoid addressing the moral question you raise. I take it you write in the spirit of Dante: The hottest fires in hell are reserved for those who remain silent in the midst of a moral crisis. And, in that spirit, and for what it is worth, I reply.

First, some background and delineation of personal biases.

I am not a Jew, but like most Americans my sympathies, and more than that, lie solidly with the cause that Israel represents. The cause involves much more than a piece of territory; it embraces the whole set of values, whether religious, judicial or ethical, to which our civilization is heir.

I am not even sure that many American Jews themselves fully recognize the extent to which those common ties springing out of Judaism have shaped the attitudes and behavior of non-Jews in America. They have good reason to misunderstand. Their history in this country, which celebrates religious and political freedom and hails tolerance as a national virtue, too often has been one of intolerance and repression.

Prejudice against Jews always has been a mystery to me. I have never understood how anyone who professes to be a Christian, a follower of Christ, could harbor hatred against Jews as a people. Christ was, after all, a Jew, and so were all His disciples. He and they first taught the lessons Christians supposedly still use as the cornerstone of their faith: Compassion, charity, tolerance, peace. So speaking only for myself, as someone raised a Christian, who went through the traditional childhood steps of passing Bible study classes, Old Testament and New, in Sunday school, the idea of what Israel stands for remains deep and personal. I cannot see how any American, and especially Christians, can fail to be influenced by these factors, just as I am. In that sense, we are all children of Israel.

Saying that, however, in no way addresses the present situation involving the state of Israel's behavior. Again, some background.

To my mind, since World War II no greater tragedy exists than that implicit in the following terrible irony of history: The Jews, who have borne suffering and injustice while searching for their homeland, have been locked in deadly opposition to Palestinians seeking theirs. They have gained their homeland by displacing the Palestinians.

All of the events we are now witnessing revolve around that history. I am sorry to say that increasingly Israel has been acting more like the oppressor states that have brutalized its people in the past. Israel cannot claim moral superiority because of the sufferings visited upon its people unless it fully recognizes the horrors being experienced by the Palestinians.

Of all people, the Israelis should be particularly sympathetic to the plight of the Palestinians. Yet their leaders show hardly a trace of understanding and sadly little sensitivity. Worse, they seem so intoxicated by their own power, by their ability to work their will, that they are surely creating even deeper animosities. They are guaranteeing greater conflicts in the future.

Three times in the last generation the Palestinians have been forced to flee into the sort of exile that has made the story of the Jewish people one of such extraordinary woe.

The first was in 1948, when Israel was created out of land on which the Palestinians lived (and had been living there for more than 3,000 years, asserting ancestral descent from the Philistines and Canaanites whom even Jewish history recognizes as living there before the first Jews occupied the region in the days of Abraham beginning about 1600 B.C.).

The second came after the 1967 war. Every acre of Palestine, as well as parts of Lebanon, Syria, Jordan and Egypt, came under Israeli occupation. Tens of thousands of Palestinians were forced to flee. They have lived since in refugee camps. An entire generation of Palestinians has grown up in exile.

Now, the third, and most tragic example of all, stands before us.

Menachem Begin bears a heavy responsibility for the tragedy unfolding. I believe Begin's performance to be one of the most odious and arrogant of a major leader in the post-World War II era. It's hard to see how peace can result so long as he stays in power. The way he has employed his forces in the invasion of Lebanon, and the contemptuous manner in which he has repeatedly treated his allies, deserve nothing but the strongest condemnation.

That doesn't mean all the blame for this tragedy lies with Israel. The Palestine Liberation Organization has practiced a brand of terrorism that is barbaric and disgusting. The PLO has disgraced itself and is undeserving of the respect of civilized society. By their actions, members of the PLO have sullied the just cause they claim to represent. No wonder other Arabs have been so singularly reluctant to take these assassins inside their borders. And history is seldom an either/or situation. That is especially so in the tangled Middle East dispute born of such ancient animosities and flowing out of age-old cultural and religious battles over territory and primacy.

But, you implore me not to commit the sin of silence, or, by citing ambiguities, fail to take a position. I have tried to accept your challenge. Finally, I would add this:

The United States cannot continue to be true to itself and countenance such actions as have been occurring in the Middle East. Begin and Israel must be made to understand that unmistakably. He and they cannot be permitted to misuse American defensive weapons, not only in direct contradiction of our laws, but in opposition to everything America stands for: freedom, self-determination, fair play and simple decency to our fellow human beings.

Sincerely,

Haynes Johnson