In this city, wonderfully lumpy with unmelted ethnic neighborhoods, in Ukrainian restaurants on Oct. 3 glasses will be raised to celebrate Walter Polovchak's birthday. The littlest defector is not so little now. He will be 18 and secure from the Soviet regime and the American Civil Liberties Union.

Walter was born in the Ukraine. When he was 12, his parents were allowed, inexplicably, to emigrate to the United States. Walter's father indicated his intention to return: instead of selling his home, he "lent" it to a neighbor and gave other possessions to a KGB official. The Soviet Embassy in Washington pressured the father to require Walter and his sister to return with him. The sister soon turned 18 and was safe. Walter, having seen what makes America great -- freedom and the Chicago Cubs -- sought asylum. The ACLU sided tenaciously with the father. It is deplorable that only the calendar -- Walter's birthday -- not America's courts gave Walter a decisive victory.

The closing of Walter's case coincides with the publication of a book ("The Politics of the ACLU," by William Donahue) that shows how the ACLU has become a lobby for the left's agenda. The ACLU's support for the right to distribute child pornography or use heroin is less illuminating than this: Racial quota systems, once vigorously opposed, now are as vigorously supported. This illustrates the ACLU's result-oriented approach to constitutional rights.

Aaron Wildavsky, political scientist at Berkeley and a former ACLU member, says the ACLU has reversed traditional American thinking about equality. The traditional sequence has been: Equality of rights guarantees equality of opportunity, which will produce satisfactory equality of conditions. The ACLU reverses the sequence: Equality of condition is a prerequisite for equality of opportunity in the exercise of equal rights.

The contradiction in the ACLU program is that a government promoting equality must be powerful, but the critique of society implicit in the ACLU's ideology undermines governmental authority. It does so by defining government as the keystone of the "system" that sustains unequal conditions and therefore makes a mockery of rights and opportunity.

Another glaring ACLU contradiction concerns children. Children once were chattel of their parents, but intelligent laws have limited parental discretion -- regarding the employment, schooling and medical care of children. No one, least of all the ACLU, says the law should not abridge parental sovereignty or take cognizance of children's rights.

The ACLU believes the civil rights of a child under 18 include the right to have an abortion even when both parents are opposed. Indeed, the ACLU believes a minor's civil rights are violated if her parents are even notified when she acquires contraceptives from a federally funded clinic. The ACLU has detected civil rights ravishments in school dress codes.

Fifty states would remove Walter from the custody of parents who abused him. But the ACLU, which would fly to court to fight any employer who tried to pay Walter less than the minimum wage, supports the right of Walter's father to commit the ultimate and unappealable abuse of consigning him forever to a prison society.

Alan Dershowitz is a professor at Harvard Law School and a hyperkinetic litigant on behalf of civil liberties. He says the ACLU's behavior regarding Walter, seen in the light of policies regarding children's rights to abortions and other matters, can be understood only in terms of "an unwillingness to criticize communism."

ACLU advocates say that those judicial and other government actions that helped Walter were "political" in that they took cognizance of the nature of the Soviet regime. But of course. The problem would have been different had Walter been resisting return to, say, Denmark, where he would have been free to decide his future. Suppose Walter were black and resisting return to South Africa. Who believes the ACLU would have opposed him? While the ACLU was opposing him, the New Jersey ACLU was defending a child in a case similar except for the fact he was resisting return to Chile.

Walter's case involved ludicrous governmental brooding about whether, were he returned, he would face persecution. The Soviet regime, which tortures its most distinguished citizen, Andrei Sakharov, would take up where it left off with Walter who, as punishment for his Catholicism, was kept at school on Christmas Eve to chant Leninist slogans. Ten years of comprehensive noncompliance with the Helsinki Accords demonstrates that the Soviet regime persecutes everyone guilty of an appetite for freedom.

Walter's case is a splendid and timely embarrassment for the various Washington bureaucracies that are toiling to produce an atmosphere of false cordiality for the summit. The cordiality is supposed to facilitate the achievement at the summit of . . . more accords.