THE NEW PROTEST against human-rights violations in Vietnam is an eye-opener not so much for its substance as its signers. Organized by Joan Baez, the group includes many of the notables of the anti-war movement of the 1960s and the early 1970s right up to Daniel Berrigan. The left has been debating for some time whether Vietnam, as a socialist state ostensibly devoted to social justice and as a country laboring to recover from a cruel war in which United States played a heavy part, should be held to the human-rights standards expected of other states. Although the whole anti-war movement has not come over, a good part of it now has. The Baez group, eschewing the usual excuses for Stalinist practices, accuses Vietnam of holding large numbers of political prisoners and of mistreating them, often savagely.

That it is a year or two - 10? 20? - after various other people started questioning Vietnam's dedication to human rights is bound to be remarked on. No good purpose would be served, however, by ideological recrimination. The important thing is that, on the left at least, the double standard for judging regimes of the right and left is being undermined. That standard needs, of course, to be dealt a blow on the right as well. It is in a concern for the victims of arbitrary state power of all stripes that Americans should unite. Certainly there is no shortage of victims in Vietnam, a place, or phenomenon, which continues to wield an almost uncanny power to affect American moral and political sensibilities.

Will the victors in Hanoi, who dismiss human rights appeals from those who did not support their struggle for power, respond to those who did? The Vietnamese may not be deeply troubled by the "personal disappointment" expressed by Joan Baez and her Humanitas/International Human Rights Committee. Yet Realpolitik may well incline them to note that, by their contempt for human rights, they are losing a valuable consistency. Unquestionably Hanoi needs Western trade and technology, not to speak of easy development loans, and presumably it needs a Western political link to avoid growing dependence on the Soviet Union. It makes the achievement of these goals ever more remote by isolating itself from those in the West disposed to deal with it fairly.