Born and raised in Israel, Karsh graduated in Arabic and Modern Middle East History from the Hebrew University in Jerusalem, and obtained an MA and PhD in International Relations from Tel Aviv University.

After acquiring his first academic degree in modern Middle Eastern history, he was a research analyst for the Israel Defence Forces (IDF), where he attained the rank of major.

He has held various academic posts at Harvard and Columbia universities, the Sorbonne, the London School of Economics, Helsinki University, the International Institute for Strategic Studies in London, the Kennan Institute for Advanced Russian Studies in Washington D.C., and the Jaffee Center for Strategic Studies at Tel Aviv University.

He has published extensively on Middle Eastern affairs, Soviet foreign policy, and European neutrality, and is a founding editor of the scholarly journal Israel Affairs. He is a regular media commentator, has appeared on all the main radio and television networks in the United Kingdom and the United States, and has contributed articles to leading newspapers, including The New York Times, The Los Angeles Times,The Wall Street Journal, The Times (London) and The Daily Telegraph.

Reviewing Empires of the Sand, by Karsh and his wife Inari, in The New York Times, Richard Bernstein characterized it as:

Amir Taheri, in the Sunday Telegraph, said of Islamic Imperialism:

Robert Fulford in the Canadian National Post said of Islamic Imperialism:

Reviewing Empires of the Sand, Dr. Anthony Toth (D.Phil, Oxford) says:

In response to one particular attack by Karsh on the work of the New Historians, Benny Morris said that:

Reviewing Fabricating Israeli History, Morris later said:

The political scientist Ian Lustick describes Karsh's writing in Fabricating Israeli History as malevolent, and the nature of his analysis as erratic and sloppy. The book, he wrote, was ripe with 'howlers, contradictions and distortions'. Lustick cites six instances where Karsh, he alleges, presents quotations the originals of which state the very opposite of what Karsh tells his readers they say. One such, says Lustick, is a statement by Golda Meir alluded to by Karsh in support of his argument that there was never an agreement between Abdullah of Transjordan and the Zionist leadership. In the original, says Lustick, Meir explicitly states that there was an agreement: 'The meeting [in November 1947] was conducted on the basis that there was an arrangement and an understanding as to what both of us wanted and that our interests did not collide'.

Yezid Sayigh, Professor of Middle East Studies within the Department of War Studies at King's College London, has written of his King's College colleague that, "He is simply not what he makes himself out to be, a trained historian (nor political/social scientist)," urging "robust responses [that] make sure that any self-respecting scholar will be too embarrassed to even try to incorporate the Karsh books in his/her teaching or research because they can't pretend they didn't know how flimsy their foundations are." Karsh, citing his own doctorate in political science and international relations, and undergraduate training in modern Middle Eastern history and Arabic language and literature, retorted that Sayigh's remarks were "not a scholarly debate on facts and theses but a character assassination couched in high pseudo-academic rhetoric".

Richard Bulliet, Professor of History at the Middle East Institute of Columbia University, describes Empires of the Sand as:"a tendentious and unreliable piece of scholarship that should have been vetted more thoroughly by the publisher" and asserts that the authors failed to "contribute a dimension of sense and scholarship that raises the debate[s in question] to a higher level." Karsh in response wondered "what credential did Bulliet possess, that a leading journal in the field should ask him to review our book? He is a medievalist who has done no research or writing on the subject. But in his spare time, he propagates the view of the Middle East and its nations as hapless victims of Western imperialism".

• Homepage at King's College London

Articles by Karsh

• "Arafat Lives", Commentary, January 2005, pp. 33—40. Reprinted in Ha-Umma (Hebrew)
• "Israel's Arabs v. Israel", Commentary, December 2003, pp. 21—27]
• What Occupation?
• Benny Morris and the Reign of Error
• Benny Morris' Reign of Error, Revisited, a review essay on Morris' revised edition of his book on the Palestinian refugee exodus.
• Dear Diary: Juan Cole's Bad Blog
• "Were the Palestinians Expelled?"
• "European Misreading of the Israeli-Palestinian Conflict: Finnish Foreign Minister Tuomioja - A Case Study"
• The Unbearable Lightness of my Critics
• Beirut Bob, a review by Karsh of Robert Fisk's The Great War for Civilisation.