Time magazine last week published an utterly riveting photo of President Lyndon Johnson, one that not even family members had seen before. It shows him alone and completely bent over in a posture of distress, sitting at a White House table on which rests one of those old tape players with two big reels. The caption reads: "L.B.J. is overcome by Son-in-Law Charles Robb's taped account of losing men in battle."

This is the man so often savaged as a monster, who faced a characteristic taunt that altogether denied him feeling and an inner life: "Hey, hey, LBJ / How many kids did you kill today?" Or did the taunters instinctively know, as schoolyard children know, what would most hurt the commander-in-chief, with two sons-in-law in the war?

I called Robb, now governor of Virginia, who said he was deeply moved by the photo; he had not seen it. "It shows a side he did not want to share. Yet had he shared it, he would have been much better understood." Why didn't Johnson want that compassionate side seen? "Because -- I'm only speculating -- it might have sent a mixed political message: he couldn't exhibit doubt or concern or human emotion" -- to Hanoi. Robb went on to underline the deep compulsion he said Johnson felt "to go to people in need, to be with them."

Robb said he never sent his father-in-law tapes, but his wife, Lynda Bird, gave him a recorder when he went to Vietnam, and he taped personal messages to her. Johnson asked to hear parts of them. Robb did not tape accounts of "graphic violence," he said, "but I talked about people, and this would have had an emotional impact on him." Apparently this was what Johnson was listening to in the scene photographed.

From reports at the time and from his memoirs, one knows it pained Johnson to send family members -- and not only his own family's members -- into combat. But of course he did it. The result of doing his duty as he saw it destroyed much of his presidency and ravaged the man.

There is a poignant dilemma here, one not limited to but certainly characteristic of Washington: Fathers who are men of power can be called upon to make decisions affecting the very lives of their sons. Even citizens in less exalted positions must consider, as they shape their views on, say, Vietnam or Nicaragua, whether it may mean their sons will go to war.

In my time in this town I have met only one person who said to heck with foreign policy, all he cared about was that his kids should not be killed. But what would we think of a president who made decisions of war and peace on that basis? We would impeach him. It would be a violation of his oath.

You do not have to be in the peace movement, however, to believe that impeachment might also be the just deserts of a president who made war and peace decisions without considering his sons. Duty is a stern master and favoritism is forbidden, but some measure of personal compassion and family feeling is an essential and reassuring presidential trait.

In Johnson's case one can guess he found it grimly right, perhaps necessary, that Robb, a Marine who sought out combat, and later Pat Nugent did not avoid the perils to which his orders were exposing so many others. One can further guess that the two young men were acutely aware of the special demands imposed on them by their marriage into the first family. Robb, for instance, in his direct communications with Johnson, "wrote in an upbeat way. I did not want to add to his burdens."

In the Vietnam years one often heard (mostly approvingly) of government officials who had been turned against the war, privately or emotionally anyway, by their children -- by their civilian children, since few children of the Washington establishment went to war.

Such turns, however, were not available to the commander-in-chief. He was bound by the code of the public servant to take decisions on public grounds. He could not have yielded to private discussions around the family dinner table, or to words on tapes.

Not this president, not fighting this war: Lyndon Johnson was responsible for the morale of the armed forces, and his whole strategy was based on projecting American will to Hanoi. A display of vulnerability to family sentiment would have been seen as a crippling political weakness. Surely Robb is right in suggesting that this is why the photo did not appear in Johnson's time. It is an image of pure tragedy.