Kurt Waldheim, the erudite diplomat who served as U.N. secretary-general and Austria’s president but left the world stage a pariah after his Nazi past was exposed, died yesterday. He was 88.

Austrian state media said Waldheim, who was hospitalized last month with an infection, died of heart failure in Vienna, Austria.

The case that defined the legacy and memory of the longtime diplomat was built around a grainy black-and-white photograph that showed a young Waldheim — tall, lean and uniformed — as he fought for a Nazi army unit blamed for wartime atrocities in the Balkans. Other pieces of evidence included logs and intelligence reports, purportedly bearing his signature, describing mass deportations of Greek Jews to death camps.

The controversy surrounding Waldheim was particularly problematic for Austria, forcing a tardy reckoning of the nation’s complicity in Nazi crimes. Austria had continued to portray itself as a victim of the Third Reich, rather than its collaborator, long after Germany was paying reparations and banning neo-Nazi groups.

Waldheim’s initial denial of his Nazi past and obfuscation mirrored that of a nation. And while the scandal around him kicked up new poisonous clouds of anti-Semitism, when he finally left public life, in disgrace, Austria also began a slow process of recognizing its sins.

He had risen to the pinnacle of international diplomacy and was running for president of Austria when his Nazi past caught up with him. He went on to win the presidency in 1986, and less than a year later, the American government formally barred him from entering the country, citing evidence it said showed that he had “assisted or otherwise participated” in the persecution of Allied prisoners, Yugoslav partisans, Jews, and other civilians. The ban was never lifted.

For much of his adulthood, Waldheim claimed that he was drafted into the German army after Adolf Hitler occupied Austria but sat out most of the war, attending law school in Vienna, because of a shrapnel wound he suffered on the eastern front in 1941. That claim was repeated in two autobiographies and routinely to journalists. Eventually, though, he was forced to acknowledge that he continued in the military as an intelligence officer, stationed in Greece and Yugoslavia from 1942 to 1945 — sites of some of the most horrendous massacres of the war.

Still, he denied any role in war crimes. Only after a blue-ribbon historical commission concluded in 1988 that Waldheim knew about and failed to prevent deportations and other atrocities did the former U.N. secretary-general admit that he knew what the Nazi regime was doing. Even then, he evaded moral responsibility.

“To deduce that knowledge constitutes some kind of crime is simply not correct,” he told an Austrian television interviewer.

Nearly a decade later, he brought himself to accept that lying about his past was wrong. Beyond that, though, he continued to deny an active role in widespread executions and abuse and blamed his downfall on a conspiracy by American Jews.

“As a member of the German Army, I did what was necessary to survive the day, the system, the war — no more, no less,” he wrote in the 1996 book, “The Answer.”