“I’m not defaming anyone,” said the Polish American historian Jan Gross, a tall, angular man with a shock of snow-white hair. “I’m just trying to tell the truth.”

Gross, 66, a professor of war and society at Princeton University in Princeton, N.J., was rebutting criticism of his books, which have hit a raw nerve in some Polish quarters.

For about a decade now, Gross has been no stranger to controversy, having written three hard-hitting accounts of the Holocaust and the postwar period in Poland that have polarized public opinion in his native land and the Polish diaspora.

Neighbors: The Destruction of the Jewish Community in Jedwabne, Poland, published in 2001 and a National Book Award finalist, explores a pogrom in a Nazi-occupied Polish town in the summer of 1941 in which upward of 1,600 Jews were slaughtered by their Catholic neighbours.

Fear: Antisemitism in Poland after Auschwitz, published five years later, examines the hostility and violence to which Polish Jews were subjected upon returning to their homes in Poland after World War II.

Golden Harvest, which he wrote with his wife, Irena Grudzinska, came out last year and focuses on Polish “diggers” who sifted through the ashes and remains of murdered Jews in the Treblinka extermination camp in the hope of finding jewelry and dental gold overlooked by the Nazis. The gruesome activity they engaged in, he suggests, was a metaphor for the plunder of Jewish wealth during and after the Holocaust in Poland.

These books, two of which have been bestsellers, have brought Gross a measure of fame and notoriety and played a significant role in cracking open Polish collective memory of a dark epoch and launching a long-deferred debate on the explosive subject.

More to the point, Gross has been instrumental in exploding a cherished national myth that Poles, rather than having been solely victims of the brutal Nazi occupation, were also oppressors.

Critics have lambasted Gross, denigrating his methodology, questioning his facts and claiming he traded in stereotypes, prejudices and common gossip. A few have even claimed he was intent on damaging Poland’s international image.

In a nasty reference to Neighbors, Lech Walesa, the Solidarity trade unionist and a former president of Poland, contemptuously dismissed Gross as “a mediocre writer” and “a Jew who tries to make money.” Norman Davies, the British historian, claimed Neighbors was “deeply unfair” to Poles.

Walesa’s cutting remarks do not bother Gross in the least. “Someone slipped these words into his writing. He’s a good man. He didn’t read Neighbors. This is my supposition. He was under the influence of a very nationalist, antisemitic priest, Father Henryk Jankowski.” As for Davies, he said, “What happened in Jedwabne was unfair to Jews, not Poles.”

Jews in Poland have climbed on the anti-Gross bandwagon, too.

Marek Edelman, one of the leaders of the Warsaw Ghetto uprising, condemned Fear, claiming that postwar violence against Jews in Poland was rooted in banditry rather than antisemitism. In a commentary on Golden Harvest, the chief rabbi of Poland, Michael Schudrich, observed, “Gross writes in a way to provoke, not to educate.”

Responding to their attacks, Gross said that Edelman backed away from his original assessment, and brushed off Rabbi Schudrich’s comment as “silly.”

Among liberal Poles and Holocaust survivors, Gross has been praised as an important voice.

Agnieszka Magdziak-Miszewska, a former deputy editor of the Catholic magazine Znak, wrote that “the painful truth of Jedwabne” was “the most serious test that we Poles have had to confront in the last decade.” The novelist Elie Wiesel, in a review of Fear, observed it had forced Poles to reflect on their checkered past.

To Gross – a graduate of Warsaw University who emigrated from Poland with his parents in 1969 after being briefly imprisoned by the Communist regime for his involvement in a student protest movement – the reason why he has come under such sharp scrutiny is clear.

“My critics are deeply wed to a nationalist version of Polish history and are unwilling to face the truth about Poland’s past,” he said in a recent interview in Toronto. “It’s a narrative in which Poles are viewed as victims who can’t do wrong. But there are a lot of Poles, including members of the Catholic intelligentsia, who view things in a completely open-minded way.”

Asked to describe his enemies, he replied, “People who are ignorant and unwilling to learn about history.”

Yet he admits that the slings and arrows have been hurtful. “It saddens me that a segment of the public refuses to think openly about the past.” He hastened to add that he has never had an unpleasant public encounter in Poland. “On the contrary, people have come up to me to thank me.”

His books, he said, have “unblocked the story of Jewish persecution at the hands of their [Polish] neighbours.”

As a result, this issue is “openly and honestly” debated today. “I would say there has been a progressive opening up of Polish minds. Poles are increasingly looking at the Holocaust objectively.”

He is particularly pleased that a group of Polish historians, namely Jan Grabowski and Barbara Engel-King, do not flinch from exposing “Polish collusion” during the Holocaust.

Under the shadow of Nazism, Poles suffered greatly and heroically and helped Jews, paying the price in some instances for their decency, he noted.

Yet far too many Poles participated in the persecution and murder of Jews, or denounced them to the Germans. “This is a story we have to tell,” he said.

In 12 villages within the vicinity of Jedwabne, in Wasosz and Radjilow, for example, hundreds of Jews were murdered by Poles. In his judgment, these events would not have happened without Nazi provocation.

Gross said that Polish-language books about these atrocities are currently being translated into foreign languages, including French and English.

A visiting fellow at Yad Vashem in 2012, he began writing on Polish-Jewish themes after concluding that historians had portrayed wartime Polish-Jewish relations incorrectly. “There wasn’t much written on it, but it was claimed that Poles were either unable to help Jews or had provided as much assistance as possible.”

Rejecting this perhaps self-serving analysis, Gross said that wartime Polish-Jewish relations were generally unfriendly. There was a yawning chasm between Poles and Jews, with the blatant antisemitism of the prewar era having decisively influenced Polish attitudes toward Jews.

Being the son of an assimilationist Jewish father who was a lawyer and sociologist and a Catholic mother who translated French literature into Polish and helped save her husband during the Holocaust, Gross seems ideally placed to ponder the depths and intricacies of Polish-Jewish relations, past and present.

And while he believes that antisemitism in contemporary Poland is a serious phenomenon, he takes solace from the belief that Poland’s younger generation is enlightened.

Not surprisingly, Gross is optimistic about the future of Polish democracy, which supplanted four decades of communism almost 25 years ago. “It’s doing fine,” he said.