THERE IS SOMETHING both mean and frivolous about the Helms United Nations amendment, which the House takes up today.It is mean because, if sustained, it would slowly but surely sap American influence in an organization that, however imperfect and irksome, remains crucial to the United States' global business. It is frivolous because its pretext is a complaint-that its Third World majority is turning the United Nations into a soak-the-rich operation-that is factually thin.

Nobody was paying much attention when Sen. Jesse Helms (R-N.C.) got his amendment through Congress last fall. It stopped funds for technical assistance in the United States' United Nations dues on grounds that foreign aid should be voluntary. With that broad point even the State Department agrees; it has been arguing it, with fair success, for several years. Mr. Helms, however, ignored the fact that the United States has a legal treaty obligation to pay its dues, and a political interest in avoiding a precedent that would let other nations also earmark or withhold dues at will. He ignored, too the fact that the United States itself benefits from much of the technical assistance at issue (navigation, weather, disease control) and that such assistance is written into the charters of specialized agencies that this country joined long ago.

The United States is in arrears on its 1979 dues to the United Nations and many agencies whose charters prohibit them from accepting conditional payments. A country two years in arrears loses its vote, but well before that other nations will conclude that a deadbeat is not serious about the organization and, therefore, does not need to be taken seriously. This would be a blow to the Carter administration's desire to accommodate the Third World. It would be more of a blow to something we would have though a muscle-flexer like Mr. Helms appreciated: the power and influence of the United States.