Respected historian of Islam who landed in controversy after advising Bush on Iraq

Professor Bernard Lewis, who has died aged 101, was the foremost Western historian of Islam in the postwar era, an achievement all the more impressive in that, as a Jew, he was severely restricted in his access to Arab archives.

Instead, Lewis made his name through research in the Ottoman archives and, in an academic world where specialisation is increasingly de rigueur, by developing an overarching expertise in Turkish, Persian, Arabic and Jewish affairs. His linguistic mastery stretched to Latin, Greek and Aramaic, too.

Even Lewis’s enemies admitted that in Islamic studies he was unrivalled. Such was the quality of his work that his volume The

Middle East and the West (1964) was reprinted by the Egyptian Muslim Brotherhood. ‘‘I do not know who this man is,’’ said the editor. ‘‘He is either a candid friend or an honest enemy, but in either case he is one who refuses to deal in falsehoods.’’

The list of his books, professorial chairs, prizes and honorary doctorates took up more than five inches in Who’s Who.

Yet until September 11, 2001, Lewis’s most intensive dialogue was with moderate Muslim leaders such as King Hussein of Jordan and President Ozal of Turkey.

Shortly after the twin towers were brought down, however, US Vice-President Dick Cheney summoned experts, including Lewis, to the White House to discuss America’s response. In his memoir, Notes on a Century (2012), Lewis claimed that he did not advocate an invasion of Iraq, but instead suggested Western support for the northern zone of the country which, operating outside Saddam Hussein’s control, wanted to proclaim itself the ‘‘Free Government of Iraq’’ and bring down the regime from within.

Yet he did admit to taking part in ‘‘a small group discussion’’ at which President George W Bush was present. Only eight days after the attacks on the World Trade Centre and the Pentagon, Lewis was briefing Richard Perle’s Defence Policy Board, sitting next to his friend Ahmed Chalabi, the leader of the Iraqi National Congress.

When the meetings were over, Bush and Cheney were left convinced that jihadists believed that America did not have the stomach for a fight and that America had to be prepared to demonstrate strength if it wished to achieve anything in the Middle East.

Lewis blamed Arab cultural, military and technological decline since the failure to capture Vienna in 1683 – and the consequent three-century inferiority complex – for al Qaeda’s virulent hatred of the West, rather than anything specific that America had done wrong. Three months after 9/11 he warned that: ‘‘If the peoples of the Middle East continue on their present path the suicide bomber may become a metaphor for the whole region, and there will be no escape from a downward spiral of hate and spite, rage and self-pity, poverty and oppression.’’

His hawkishness derived from his loathing of appeasement before World War II and, perhaps, his closeness to a succession of Israeli prime ministers. The Wall Street Journal defined the ‘‘Lewis Doctrine’’ as ‘‘seeding democracy in failed Mid-east states to defang terrorism’’.

Lewis felt it might be possible to use minimum force to return consensual political institutions to Mid-East, starting with Iraq. With its oil wealth, large middle class, stable past and secular society, he argued, democracy had a better chance of taking root there than almost anywhere else in the Islamic world.

So, whether or not he advised Bush to mount an attack on Saddam Hussein, Lewis became famous as the British eminence grise behind the American neo-conservative architects of the invasion of Iraq. Inevitably, this was a controversial position to be in.

Some scholars, notably Edward Said, vilified him as an ‘‘orientalist’’ – an apologist for imperialism and Zionism. Many of Lewis’s friends, too, were dismayed that his association with a policy of implanting democracy in the Muslim world by force had overshadowed his enormous achievements as a linguist, historian and researcher.

Bernard Lewis was born in 1916 at Stoke Newington, north-east London, to a Jewish immigrant father and an Anglo-Jewish mother. He first became interested in oriental languages when learning Hebrew for his bar mitzvah. He went on to learn Aramaic and Arabic, and History at the School of Oriental Studies (later Soas). He also learned Latin, Greek, Persian, and Turkish.

Lewis remained at Soas to take a doctorate on the History of Islam and undertook postgraduate studies at the University of Paris. He undertook his first trip to the Middle East in 1937, enrolling at Cairo University. A year later he was offered the post of assistant lecturer in Islamic history at Soas.

During World War II, Lewis served in the Royal Armoured Corps and Intelligence Corps in the Middle East in 1940-41, before being seconded to the Foreign Office. He remained tight-lipped about his time with wartime MI6, invoking the Official Secrets Act even 70 years later.

After the war, he returned to Soas, and in

1949, at the age of 33, was appointed to a new chair in Near and Middle Eastern History.

Lewis began his research career with the study of medieval Arab, especially Syrian, history. After the creation of the state of Israel in 1948, however, scholars of Jewish origin found it increasingly difficult to conduct research in Arab countries.

Lewis therefore switched to the study of the Ottoman Empire, while continuing to research Arab history through the Imperial Ottoman archives, to which he was lucky to become the first Westerner admitted. ‘‘Feeling rather like a child turned loose in a toy shop, or like an intruder in Ali Baba’s cave, I hardly knew where to turn first,’’ he recalled.

Lewis came to the conclusion the decline of the Middle East was a largely self-inflicted condition resulting from both culture and religion, challenging the conventional view that it was a by-product of European colonialism.

In 1947 Lewis had married Ruth Oppenhejm. But in 1974, after he had a brief affair with an Ottoman princess, the marriage was dissolved. He emigrated to America, where he took up a chair in Near Eastern Studies at Princeton.

In Muslim Discovery of Europe (1982), Lewis argued that Muslim societies could not keep pace with the West and that ‘‘Crusader successes were due in no small part to Muslim weakness’’. Islamic societies were decaying from as early as the 11th century, primarily due to internal problems like ‘‘cultural arrogance,’’ which prevented creative borrowing, rather than external pressures like the Crusades.

In addition to his scholarly works, Lewis wrote books for a wider readership including

The Arabs in History; The Middle East and the West (1964); and The Middle East. Public interest in Lewis’s work increased after 9/11.

What Went Wrong? (2002, but written before the attacks) became an instant bestseller, as did The Crisis of Islam (2004).

After his retirement from Princeton in

1986, Lewis taught at Cornell University until

1990. He is survived by his son and daughter.

– Telegraph Group