The US historian Robert Paxton is famous for dismantling French myths.
He demolished the idea that its collaborationist wartime regime had "passively resisted" German occupiers in his 1972 book "Vichy France", which also delivered the bombshell that the French Resistence was rather slow in resisting.
Now he has taken his knife to the winner of France's pre-eminent literary award, the Prix Goncourt.
His deadpan evisceration of "The Order of the Day", Eric Vuillard's historical novel that reconstructs a notorious 1933 meeting at which German industrialists agreed to back the Nazis, has left the French literary world agog.
Damning the "slenderest volume ever awarded the prize" with faint praise, the veteran historian slowly unpicked what he saw as its historical errors and approximations, before dismissing it in a devastating final flourish.
"Many major 20th-century French authors - Gide, Sartre, Camus, Celine and Colette - never received the Goncourt," he wrote in the New York Review of Books, reviewing the English translation of the novel.
"Will Eric Vuillard be among the winners who are long remembered? There is reason to doubt it."
But Vuillard, who made his name with books that are detailed reconstructions of historic events such as the storming of the Bastille which sparked the French Revolution, did not take the criticism lying down.
He replied in kind with a letter to the Review in the "gritty and physical" prose style that Paxton had backhandedly praised, with some "swarming details" of his own about the 86-year-old Columbia University professor.
Withering retort
First he took Paxton to task for "scolding me first and foremost for being 'opinionated'.
"That reproach supposes the existence of a distant, neutral way of writing," Vuillard added, before attacking Paxton's Olympian academic objectivity by damning him with his own words from the past.
He dug up an interview in which Paxton had praised as his "master" the controversial French historian Raoul Girardet, a disciple of the far-right anti-Semitic thinker Charles Maurras, the leading light in the collaborationist Action Francaise movement.
Vuillard, 50, pointed out that Girardet was jailed for supporting a failed military coup to overturn the elected French government in 1961 and stop Algeria being granted independence.
And he twisted the knife by recounting how Paxton had called a book by Girardet which praised the colonial Rif War waged by France and Spain on Moroccan Berbers, in which poison gas was used on civilians, as "having played a major role in his own intellectual development".
Paxton - who had been withering about the Goncourt jurors "who name their own replacements" - shot back straight away on the Review's letters page that he had nothing against historical fiction, as long as it was good.
"Good fiction needs no utilitarian justification, but it can contribute powerfully to history teaching. Some novels do this better than others," he added acidly.
"The Order of the Day" was hailed with glowing reviews in France and Spain when it was first published in 2017, tapping into popular distrust of big business.