T IS NOT news that some ultraconservative groups have long opposed ratification of the Genocide Treaty. For decades, alarmist lobbies and isolationist publications have been issuing warnings of the dire consequences that would befall Americans if the pact, signed 36 years ago, were agreed to by the Senate. Innocent citizens, we were told, would be hauled off for criminal trials before the World Court and sent to prison in Iran or Nicaragua. American soldiers would be subjected to humiliating public trial by scheming communists. Third World dictators would be able to override the U.S. Constitution. Such unfounded fears have led to the adoption of two reservations by the Senate Foreign Relations Committee, which reported the ratification resolution this week.

The treaty, which has been accepted by 96 nations, makes it an international crime to kill or seriously harm members of a religious, racial or ethnic group as part of a plan to destroy that group. If the United States were to ratify the treaty, Congress would then have to pass legislation implementing it here. The World Court does have responsibility under the treaty to interpret its language, but since the court cannot conduct criminal trials or order sanctions of any kind except through the United Nations Security Council, where the United States has a veto, there should be no fear that the agreement requires abandoning American citizens to some international tribunal.

Sen. Jesse Helms offered two reservations, one requiring Washington's special consent to World Court jurisdiction in cases involving the United States, and another asserting that Americans are not obligated to enact legislation contrary to the Constitution. These reservations purport to save us from a terrible fate. In fact, the United States has never beenthreatened.

The resolution of ratification now goes to the floor encumbered with these superfluous reservations. But while they are undesirable, they do not seriously undermine the treaty, and it would be foolish for senators who have long and faithfully supported ratification to abandon the measure because of Sen. Helms's small victory. It is humiliating for the United States, in ratifying, to signal uncertainty about its ability to defend itself against unfounded charges of genocide. But even if the reservations cannot be eliminated by the full Senate, ratification should go forward.