The lifting of the Rev. Ian Paisley's visa is but the latest episode showing that Americans need to clarify and improve their role in relation to Northern Ireland's tragic conflict. Too many Americans - and even one would be too many - are still giving money to IRA terrorism. Too many of their representatives are speaking incautiously, as did Deputy Secretary of State Clark when he created a furore by saying in Dublin that all Americans hope for an eventually unified Ireland.
Now Mr. Clark has revoked the visa of Mr. Paisley, who was scheduled for an American tour to speak against a unified Ireland and in favor of Northern Ireland's continued union with Britain. No one has to take sides on this matter to be concerned about an apparent closing of America's free-speech doors to the most publicized partisan on one side of the argument.
Roman Catholic lobbyists against the Protestant clergyman's visit cited an earlier US refusal of entry to IRA supporter and former hunger striker Owen Carron. Both men have been alleged to encourage violence. Mr. Clark spoke of Mr. Paisley's ''divisive tone'' in ruling that his presence would be ''prejudicial to the US public interest.'' But both men are also members of the British Parliament available to the international media. Why prevent either of them from speaking on US soil? It is both futile and out of keeping with the American tradition of letting all ideas be sounded so that the public can choose between the tares and the wheat.
Not that any peace-loving American could hold any brief for the inflammatory extremist attitude with which Mr. Paisley expresses his views. Last month he was suspended from Parliament for disorderly conduct. His condemnation of current Anglo-Irish efforts at conciliation can hardly serve the peace process. Giving him an American platform might even risk slowing that process.
But free speech and the exposure of spokesmen to the public are worth the risk. Washington has taken the risk with controversial figures before. Ian Smith was not excluded when he was obstructing peace efforts in Zimbabwe. Just recently Jonas Savimbi of Angola was not excluded though he is a known leader of guerrillas opposed to the government there. And, of course, the rulers by force of such vast countries as the Soviet Union and China have been not only admitted but officially welcomed to the United States.
To say no to Mr. Paisley, as noted at the beginning, is simply to remind Americans how much they need to improve their policies and practices in regard to Northern Ireland.