FROM ONE MAN'S chance reading of a single paragraph in an Austrian magazine, a stunning and saddening body of material has accumulated bearing on the wartime role of Kurt Waldheim, a former secretary general of the United Nations and, currently, a candidate for the presidency of Austria. The reading, by an official of the World Jewish Congress, led to the combing of forgotten and in some cases hidden files indicating that in 1942-45 Mr. Waldheim, far from being the war-wounded law student that he had claimed to be, actually was serving as an officer in units fighting the Nazi war in Yugoslavia and Greece.

The questions arising from this grim inquiry are taking ever more painful shape. Is Mr. Waldheim, who has now admitted concealment of his 1942-45 war service, also concealing participation in the gross war crimes for which his commanding officer, among others, was tried and executed? Why was it that the Yugoslavs, who at one point had classified him too as deserving prosecution for murder and killing hostages, did not prosecute him and held silence on the charges thereafter? How could such charges, arising from material in the files of a number of countries as well as of the United Nations, not have come to light in some other way? Is there the slightest substance to allegations that the information was concealed in order for someone to gain a hold over Mr. Waldheim?

Most of these questions bear inevitably on Mr. Waldheim's integrity and on the ways of official bureaucracies. There is another series of questions arising in the Austrian context. Was Mr. Waldheim acting out a certain characteristic story of Austria, the one that many Austrians have perhaps desperately wanted to believe and tell, in which they were the victims of Hitler, not his supporters and accomplices? Is not Austria facing today, in its presidential election of May 4, a nation-defining choice of whether to confront its past, ugly as some of it unquestionably was, or to stay with Kurt Waldheim in a mode of forgetting and denial?

Nobody wanted all this to happen. Mr. Waldheim could fairly have believed that his own public service since World War II, and Austria's successful integration into the postwar democratic order, had put the past sufficiently behind. But the past has its claims, truth foremost among them. On all the relevant levels an unsparing inquiry must be pressed. It is the only way.