FOR THE THOUSANDS of Palestinian and Lebanese prisoners still being held in camps by the Israeli army, conditions, though harsh, have improved to the point that the Israelis are pleased to permit occasional visits by Western journalists. As The Post's Edward Walsh reported after a recent trip to the Ansar camp in southern Lebanon, moreover, almost daily visits by the International Committee of the Red Cross are allowed. This is the important thing. The all-Swiss ICRC is the recognized expert and neutral agency in dealing with prisoners around the world with the cooperation of whatever is the holding government. Its visits offer reasonable assurance that at least minimally acceptable standards of treatment are observed.

For a whole other group of Palestinian and Lebanese prisoners in Lebanon, however, the comfort and protection of regular ICRC inspections are not available. An estimated 2,000 or more prisoners are being held in Beirut by the Lebanese army and the militia of the Phalange. Israel allows ICRC access to its prisoners. So do Syria and the PLO, whose eight Israeli prisoners are expected to be swapped for those held by Israel in the negotiations now going on between Lebanon and Israel. Lebanon, however, though it signed the 1949 Geneva Conventions creating the ICRC, has ignored repeated appeals to let the ICRC into its prison camps. In December, correspondent David Ottaway cited reports that, in the past several months, Lebanese army soldiers had killed five Palestinian detainees by torture or mistreatment and beaten scores more. The army's subsequent denials had to be read against its barring of the ICRC.

The situation of the Israeli-held prisoners has drawn the close and fervent attention of organizations with an interest in Palestinian rights. But a number of them, including the American Friends Service Committee, Oxfam and the American Arab Anti-Discrimination Committee, appear to have averted their gaze from what is without doubt the more serious current situation of the Lebanese-held prisoners. More is involved here than the reputation of groups claiming to speak under the banner of human rights. There is the welfare of thousands of Palestinians who happened to fall into the hands of one army rather than another. It would be good to see all groups joining in an appeal to Lebanon, and to the militias, to open up their camps to the ICRC.