During Kurt Waldheim's decade as secretary-general of the United Nations he would sometimes muse in private about the part of his job hidden from the public view. It was when the power of his ''powerless'' office could be exercised - a moral power as he rightly saw it. Perhaps it was an occasion when he simply invited two UN antagonists into his office.Maybe it was awkward for them even to speak to each other. He would be the go-between. He would see hardened positions soften a little. An agreement would be reached.
Such moments meant a lot to Mr. Wald-heim when he was being criticized in bureaucratic terms or for this or that venture on the international stage. And they should mean a lot to everyone interested in substituting conciliation for conflict among 156 countries - almost 30 more, incidentally, than when Mr. Waldheim began his UN tenure.
Now that he is about to pass the baton to a new secretary-general, he deserves the world's "well done."