You can show JW involvement with their own publications. They should be much more likely to believe their own literature than UN literature.
"The wild beast that you saw was, but is not, and yet is about to ascend out of the abyss, and it is to go off into destruction. And when they see how the wild beast was, but is not, and yet will be present, those who dwell on the earth will wonder admiringly, but their names have not been written upon the scroll of life from the foundation of the world." Revelation 17:8 NWT
"We cannot but admire the high principles embodied in the proposed League of Nations, formulated undoubtedly by those who have no knowledge of the great plan of God. This fact makes all the more wonderful the ideals which they express. For instance, it has been made plain by President Wilson and the advocates of his ideas that the proposed League of Nations is more than merely a league to enforce peace. They would not have us consider it to exclusively from the standpoint of politics or of military relations. It should be considered as fully from the economic and social points of view. The President's idea seems to be that the League of Nations which he proposes would stand for world service rather than mere world regulation in the military sense, and that the very smallest of nations shall be participants in its every arrangement. In other words, his idea undoubtedly is that the league shall not be established merely for the purpose of promoting peace by threat or coercion; but that its purpose, when put into operation, will be to make all nations of earth one great family, working together for the common benefit in all the avenues of national life. Truly this is idealistic, and approximates in a small way that which God has foretold that he will bring about after this great time of trouble." Watch Tower February 15, 1919 p.51 reprints page 6389