That photograph of the stern American president rebuking the Israeli prime minister by phone from his Oval Office tells, as intended, part of the story. But not all.

The mere fact that it was taken and carefully made public by the White House speaks volumes. It stands as a sharp example of the changes occurring in U.S. posture toward Israel and the Mideast.

If such a conversation had taken place between Ronald Reagan and Menachem Begin six months ago, almost certainly it would have remained private. Now, instantly, the substance and harshness of the president's criticisms are spelled out fully by the White House. And a photograph, recording the moment and capturing the emotion of the presidential displeasure, is immediately released to the press.

Naturally, as the White House knew it would, the picture dominated newspaper front pages across the country, and probably the world.

It delivers other messages. To Israel, it says continued attacks on West Beirut during delicate negotiations could jeopardize future U.S. support, whether military or economic. To the Arab states, it signals that the United States intends to pressure Israel to stop the bloodshed and get on with negotiations.

There is, of course, more to the picture than we see.

What, for instance, was said during another Oval Office phone conversation that occurred a few minutes before the now-celebrated Reagan-Begin exchange?

It is being reported, by people who have proved reliable to this reporter in the past, that Saudi Arabia's King Fahd told the president in their phone conversation 20 minutes before the one with Begin of growing Arab anger over the situation in Lebanon. And, it is said, Fahd raised the prospect of withdrawing $100 billion in Saudi funds from U.S. banks.

Similar hints, or explicitly voiced intentions, from the Kuwaitis also are being discussed privately among responsible people in Washington.

How much of this is real and how much high-level rumor is not yet clear. But, coming at a time of worsening economic conditions worldwide, they indicate that events in the Middle East are reaching a critical stage. At the least, the outcome there holds consequences far beyond the besieged geographical territory.

In that connection, in recent weeks, prompted by the belief that a columnist ought to share differing views and perspectives with readers, I have been trying in this space to enter into a public dialogue about the Mideast. Here, to close that chapter for now, are two last opposing positions from readers that I believe to be especially provocative.

The first comes from an Arab, who takes me to task for subscribing to the premise of Israel's "undisputed" right to its territory, and then asks, "Whence this right?" He writes:

"Allow me to impose on you with the following: It would seem that if a 'state of Israel' is to be created, upon the determination of the 'Powers That Were' at the time, the historical inhabitants of the area -- the Philistines or Palestinians -- must be persuaded of the justice of this act, acquiesce to the establishment of a foreign people on their land, and be willing to give up a sizable portion of their territory to accommodate the newcomers, in order for the sovereignty of the new state to be valid. There can be no credence given to the argument for a long-deferred homecoming to the land of biblical heritage, after an absence of almost 2,000 years. The Roman Empire cannot be today called to task for the Diaspora that turned the Jews of ancient Palestine into a people dispossessed, any more than the Palestinians can be made to bear the burden of guilt engendered by the 'Holocaust.' They had no part in it.

"The Palestinians and neighboring Arab nations have made consistently and amply clear for many decades, even prior to the Balfour Declaration of 1917, which backed creation of a Jewish home in Palestine but one which would not 'prejudice the civil and religious rights of non-Jewish communities' , their opposition to Zionism, and a Zionist state created on Palestinian land. How then do we find conferred on Israel an 'undisputed' right to exist? Arab protestations regardless, the state of Israel came into existence in 1948, created by force of arms, and it is maintained by force of arms in the face of undiminished Arab enmity. Israel and its supporters find this obdurate and seemingly futile Arab refusal to accept an iniquitous 'fait accompli' incomprehensible and unreasoning. 'Be realistic,' the Palestinians and the Arabs in general are being told. 'Israel is here to stay, so like it or lump it.' And they have unaccountably preferred to lump it for over three decades, and have taken many brutal lumps over the years, many more than they have been able to deal. This Arab obstinancy should have given pause to the promoters of this state, for it would appear that, in the Arab view at least, Israel's only 'right' to exist is that of overwhelming 'might,' and it is Israel's tragedy, as well as that of the Arabs, for there seems to be no way out of a perpetual and escalating cycle of bloodshed . . . . "

The second comes from a Jewish reader who responds critically to the suggestion that Israel's present actions in Lebanon should be weighed against the special dream of righteousness that somehow ought to be expected of the Jewish people:

"As to the question of Israel's moral stature before and after Lebanon: Your column made me think of myself, or at least the person I used to be. Long ago, it now seems, in my appallingly naive youth, I was a foot soldier in the army of Martin Luther King. I was one of the comfortable young whites who marched and sang and even, in my case, went south for a year to work in the cause. Well, of course I was motivated in part by the obvious rightness of the movement's aims, but also largely by Dr. King's sterling moral character -- the extreme purity of nonviolence as a political approach. And imagine my later bitterness and disillusionment when I discovered that my supposed beneficiaries were mere humans, and even worse, humans uninterested in my sensibilities and fantasies. They have their own psychic agendas, quite irrelevant to ours, and born of their own bitter experience and perception of reality.

"The Jew and the black occupy different roles in the fantasy life of Gentile America, but each can offend by getting out of their proper moral place. Dr. King drove whites to rage and incoherence by being more moral than blacks 'ought' to be. Israel is doing the same by being less moral than Jews 'ought' to be. I suppose that the burden of guilt white people carry about the history of blacks makes the idea of an independent black agenda hard to bear; how, after all, can they not bear a certain grudge? How much greater must be the guilt of feeling Gentiles about the cause of 'Judeo-Christian' civilization in its dealings with the Jews?

"Israel has done considerably less damage in Lebanon than the U.S. did in any of more than 100 six-week periods we were in Vietnam, when we had no vital interest at stake and were engaged with an enemy who could harm us only in our pride. And yet many people who supported Vietnam Helms and Goldwater, for instance carry on as if Begin were Attila the Hun. Granted that he is no Paul Newman, but the Israelis hardly count as bloodthirsty by modern standards, and these five wars since 1948 are the first ones Jews have won since the days of King David . . . . "

These pictures are as indelibly fixed in the minds of those writers as they are in the heads of millions of others on opposite sides of this equation. The question for policymakers, American, Arab and Jew, is how possibly to reconcile such sharply differing and emotionally held convictions.

Hold your breath. We approach a period where the art of diplomacy experiences one of its greatest tests, and where the consequences of failure are too serious to be permitted.