IN LIGHT OF YESTERDAY'S tragic loss of 147 American lives, feelings of sadness, anger, and frustration are appropriate. What we must add to that list, however, is regret--regret that the Marines were in Lebanon in the first place, and regret that so many young men had to die before we realized the extent of our vulnerability. The time has come for President Reagan to call home the Marines.

The fact is that the American presence in Beirut has failed. We have not "kept the peace." We have not succeeded in resolving the Syrian problem. What we did was to intervene in a conflict which was not ours to fight. More significantly, we established the Marines as sitting ducks, unable to respond offensively or defensively to an attack.

To keep them in Lebanon is futile and dangerous. It has been proven that our ambiguous involvement in the conflict does little to deter Syria's movements to control the region. And we should not sacrifice more lives to maintain this facade of positive intervention.

Others are correct in urging the US to "ponder" our initial placement of Marines in Lebanon. But we must go one step further in admitting that we erred. To withdraw from the war torn country would not be bowing to intimidation, but, rather, a responsible recognition of our mistake.