After the war, he returned to the School of Oriental and African Studies at the University of London and was appointed to the new chair in Near and Middle Eastern history.

The terms of his appointment were such that Lewis taught only one semester per year, and being free from administrative responsibilities, he could devote more time to research than previously.

Consequently, Lewis's arrival at Princeton marked the beginning of the most prolific period in his research career during which he published numerous books and articles based on previously accumulated materials.

His lecture, entitled "Western Civilization: A View from the East", was revised and reprinted in The Atlantic Monthly under the title "The Roots of Muslim Rage.

[14] His first article, dedicated to professional guilds of medieval Islam, had been widely regarded as the most authoritative work on the subject for about thirty years.

[31] However, after the establishment of the state of Israel in 1948, scholars of Jewish origin found it more and more difficult to conduct archival and field research in Arab countries, where they were suspected of espionage.

A series of articles that Lewis published over the next several years revolutionized the history of the Middle East by giving a broad picture of Islamic society, including its government, economy, and demographics.

[31] Lewis argued that the Middle East is currently backward and its decline was a largely self-inflicted condition resulting from both culture and religion, as opposed to the post-colonialist view which posits the problems of the region as economic and political maldevelopment mainly due to the 19th-century European colonization.

"[33] Further, he suggested that as early as the 11th century Islamic societies were decaying, primarily the byproduct of internal problems like "cultural arrogance," which was a barrier to creative borrowing, rather than external pressures like the Crusades.

[42] Lewis called the label "genocide" the "Armenian version of this history" in a November 1993 interview with Le Monde, for which he faced a civil proceeding in a French court under the Gayssot Law.

The court ruled that while Lewis has the right to his views, their expression harmed a third party and that "it is only by hiding elements which go against his thesis that the defendant was able to state there was no 'serious proof' of the Armenian Genocide".

[45][46] Lewis's views on the Armenian genocide were criticized by a number of historians and sociologists, among them Alain Finkielkraut, Yves Ternon, Richard G. Hovannisian, Robert Melson, and Pierre Vidal-Naquet.

[51] In 2002, he argued for his denial stance:This is a question of definition and nowadays the word "genocide" is used very loosely even in cases where no bloodshed is involved at all and I can understand the annoyance of those who feel refused.

But in this particular case, the point that was being made was that the massacre of the Armenians in the Ottoman Empire was the same as what happened to Jews in Nazi Germany and that is a downright falsehood.

[53]Lewis has been labelled a "genocide denier" by Stephen Zunes,[54] Israel Charny,[55] David B. MacDonald[56] and the Armenian National Committee of America.

[57] Israeli historian Yair Auron suggested that "Lewis' stature provided a lofty cover for the Turkish national agenda of obfuscating academic research on the Armenian Genocide".

[51] In the mid-1960s, Lewis emerged as a commentator on the issues of the modern Middle East and his analysis of the Israeli–Palestinian conflict and the rise of militant Islam brought him publicity and aroused significant controversy.

[31] U.S. Vice President Dick Cheney remarked "in this new century, his wisdom is sought daily by policymakers, diplomats, fellow academics, and the news media".

[62] Lewis advocated closer Western ties with Israel and Turkey, which he saw as especially important in light of the extension of the Soviet influence in the Middle East.

According to one source, this essay (and Lewis's 1990 Jefferson Lecture on which the article was based) first introduced the term "Islamic fundamentalism" to North America.

[66] In 1998, Lewis read in a London-based newspaper Al-Quds Al-Arabi a declaration of war on the United States by Osama bin Laden.

Lewis writes of jihad as a distinct religious obligation, but suggests that it is a pity that people engaging in terrorist activities are not more aware of their own religion:[70]The fanatical warrior offering his victims the choice of the Koran or the sword is not only untrue, it is impossible.

[70] Muslim fighters are commanded not to kill women, children, or the aged unless they attack first; not to torture or otherwise ill-treat prisoners; to give fair warnings of the opening of hostilities or their resumption after a truce; and to honor agreements.

[12] Said asserted that the field of Orientalism was political intellectualism bent on self-affirmation rather than objective study,[72] a form of racism, and a tool of imperialist domination.

"[74] Said considered that Lewis treats Islam as a monolithic entity without the nuance of its plurality, internal dynamics, and historical complexities, and accused him of "demagogy and downright ignorance".

[81] As'ad AbuKhalil has claimed that Lewis assured Cheney that American troops would be welcomed by Iraqis and Arabs, relying on the opinion of his colleague Fouad Ajami.

[62] Hirsch also drew parallels between the Bush administration's plans for post-invasion Iraq and Lewis's views, in particular his admiration for Mustafa Kemal Atatürk's secularist and Westernising reforms in the new Republic of Turkey which emerged from the collapse of the Ottoman Empire.

[83]Hamid Dabashi, writing on 28 May 2018, in an article subtitled "On Bernard Lewis and 'his extraordinary capacity for getting everything wrong'", asked: "Just imagine: What sort of a person would spend a lifetime studying people he loathes?

Similarly, Richard Bulliet described Lewis as "...a person who does not like the people he is purporting to have expertise about...he doesn't respect them, he considers them to be good and worthy only to the degree they follow a Western path".

[89][90][91] Bernard Lewis died on 19 May 2018 at the age of 101, at an assisted-living care facility in Voorhees Township, New Jersey, twelve days before his 102nd birthday.