DID YOU think the exposure of the Beirut massacre had made the city, if not all of Lebanon, safe for Palestinian refugees? How wrong you were. From Beirut come reports of the fresh abuse of Palestinians in the very camps of the massacre and elsewhere in the city. Shootings of individuals are reported. Hundreds of Palestinians have been rounded up, some briefly and others for indefinite stays in unknown places. The perpetrators are identified as soldiers of the Lebanese army. The country seethes with rumors that the government intends to run out most of the half-million or so Palestinians now there.

How can it be that the people who were the victim among victims of Lebanon's terrible summer are treated like dust in the fall? How can the perpetrators have the shamelessness and how can the United States and its partners, and the international welfare agencies, stand by?

The Palestinians in Lebanon lack a political base. Since the forced evacuation of the PLO, they have also lacked a military defender, and they stand now fully exposed to the backlash generated by the PLO's gross abuses of Lebanese hospitality. In better days, the army would be caring for all residents, refugees as well as citizens, but the army is partly the instrument of that backlash. The involved foreign governments, moreover, have it as their mission to clear out foreign armies and reduce local militias precisely so that the Lebanese army can take over. Then, to second-guess the manner of that army's assertion of Lebanese sovereignty is tricky. The international agencies are necessarily even more restricted by the host country's sovereign claims.

Still, the United States has a clear duty extending beyond the humanitarian commitment that ought to be taken for granted. The duty starts from the fact that this latest phase of the Palestinians' ordeal was triggered by an invasion by a country especially close to Washington. It continues through the obligation that Washington assumed by assuring the PLO that if it left Beirut, Palestinian civilians would not suffer as a result. It culminates in Ronald Reagan's peace plan, which requires him to earn the confidence of mainstream Palestinians.

We cannot believe that the United States, with others, cannot find ways to better protect the refugees threatened in Lebanon and to deepen the diplomatic process that alone will make possible the end of the Palestinians' status as refugees.