The Internet has its uses. But it can also be a truly awful thing.

In recent weeks I have been subjected in it to campaigns of defamation and incitement by both extremists Jews and extremist Muslims—and what appears in it is endlessly reproduced and, as it were, set in stone universally and for all time. And there is nothing effective one can really do to persuade people otherwise.

Let me give an example: Both Efraim Karsh (see his two recent pieces in American Thinker—and my two responses) trots out an alleged quote by me, in an interview I gave to Haaretz in 2004—to the effect that I supported, and support, the destruction of the American Indians. The same quote exactly is purveyed by a British Muslim video produced recently in London, entitled "Benny Morris: Historian or Racist? (LSE 14 June 2011)"—and is then buttressed by images of Indians massacred in the nineteenth century by American troops, as if to say that I was responsible for, or approved of, the massacre. Benny Morris supports ethnic cleansing and genocide, say the Muslim narrators.

But I never, ever said what I am alleged to have said, and I wrote this in a commentary in Haaretz on the interview that appeared a fortnight after the original piece by Ari Shavit. Shavit had simply misquoted me. My denial too is on the Internet—but no one ever quotes it. An allegation bandied about the Internet remains immortal, and denials will forever be ignored.

The same applies to my alleged support for "ethnic cleansing." I have said, in the 2004 interview and elsewhere, that, assailed by the Palestinian Arab militias and by the Arab armies in 1948, Israel had no choice, as a matter of legitimate self-defense, but to drive out the Palestinians from their villages and towns, which had served as the bases for their assault. But, at the same time, I have condemned massacre and rape in every circumstance; nothing can justify such acts. And, I have added, repeatedly, that I oppose ethnic cleansing and expulsion in the present as both immoral and impracticable.

But the qualifiers and context are forever removed by Internet propagandists. Thus the producers of "Benny Morris: Historian or Racist?" trot out another 2004 interview quote—that I supported the "caging" of the Palestinians—when the context, at the time, was the prevention of the daily dispatch, by Palestinian society, of suicide bombers from the West Bank's and Gaza's cities to murder en masse civilians inside Israel. I believed that they should be prevented from reaching their targets by fencing them in—by the very same security fence (often called by Palestinian propagandists a "wall," though it is 90 percent barbed-wire fence) that was then being built and which successfully ended the suicide bomber campaign. When questioned, I explained this at the London School of Economics lecture on 14 June. But of course the passage was omitted from the video.

Indeed, the video purports to deal with the lecture. But, in fact, it shows a bare five seconds of the actual one-and-a-half-hour session (the video of the session is readily available—see "Reconsidering the 1948 Arab-Israeli War" on YouTube). Me speaking—what I actually said at the LSE—is in effect completely absent. Instead, the producers give the viewer a succession of clips from subsequent interviews with Muslims and Arab-supporting Britons (some of whom may have attended the lecture) about what I allegedly said inside—all of it, of course, negative and much of it misrepresentative or downright false—and various uncontextualized and often speciously spliced quotes from my 2004 interview.

Karsh uses similar tactics in American Thinker—and both Karsh and the video producers also profusely falsify the actual history in question. Karsh pretends that Ben-Gurion and other Zionists leaders did not support transferring Arabs out of the Jewish soon-to-be state in the late 1930s and early 1940s (they did, and they made ample, clear statements to that effect). And the oh-so-softspoken narrator in the Muslim video tells us that Jews massacred "250-300 men, women and children" at Deir Yassin on 9 April 1948—when Arab researchers already in the 1980s concluded that only about 100 Arabs combatants and noncombatants died in the village that day. The narrator adds that Israel is currently engaged in "ethnically cleansing" Palestine. One may think what one likes about current Israeli policies and actions vis-à-vis the Palestinians, but "ethnic cleansing"—meaning mass expulsions—is simply not happening. It's a barefaced lie.

But on the Internet you can post and pose as you like and as much as you like. And, unfortunately, a growing number of people regard it as the primary fount of knowledge.