It has become the norm in Europe and the US for any adverse comment about Israel, however mild, to evoke a ferocious counterattack from pro-Israel groups. The fear of provoking these intimidatory reactions has prompted a widespread pre-emptive self-censorship with regard to anything Israeli or Jewish among individuals and organisations seeking to avoid them.

Scarcely any western public organisation, official or newspaper today dares to flout these strictures and pay the price. There are two main reasons for this situation: first, the deliberate conflation of hostility to Israel with that to Jews under the common and pejorative heading of anti-Semitism and second, the striking success of pro-Israel lobbyists in using their influence to stifle criticism of the "Jewish State".

It was a combination of these two factors that prompted Britain's Southampton University's decision to cancel its forthcoming conference, "International law and the State of Israel: legitimacy, responsibility, and exceptionalism".

'Toxic speakers'

I write as one of 52 so-called "toxic" speakers, as the Board of Jewish deputies describes us, who had been slated to participate in the conference, which the press has emotively and inaccurately reported to be about "Israel's right to exist".

In fact, it would have been a ground-breaking event, drawing together a large number of noted domestic and overseas scholars to examine fundamental questions about Israel's establishment and what constitutes its legitimacy.

In a democratic society that respects freedom of speech, these are legitimate subjects of debate, and the conference deserved better than to have been summarily cancelled by the university authorities. On March 30, and at a very late stage in what had been marathon preparations for the conference, the university suddenly withdrew its permission for it to go ahead.

It justified its decision on the dubious grounds of "health and safety", citing the threat of hostile public demonstrations that might have put staff, students and conference participants at risk, even though the Southampton police had stated they were adequately prepared to deal with any such problems.

There is little doubt that the university's action was the result of the pressure placed upon it by intensive pro-Israel lobbying.

There is little doubt that the university's action was the result of the pressure placed upon it by intensive pro-Israel lobbying. The Board of Deputies of British Jews, the Jewish Leadership Council and the UK Zionist Federation, which collected 6,400 signatures protesting against the conference, all made representations to the university authorities, asking them to cancel it.

Likewise, the Union of Jewish Students protested. Several MPs, including the conservative MP for Romsey and Southampton, did the same, and the Minister for Communities, Eric Pickles, called the conference a "one-sided diatribe". The conservative peer, Lord Leigh, also expressed his dismay at the conference.

Delegitimising Israel?

Tim Shacking, a mathematics professor at Southampton University, said the conference aimed to "delegitimise Israel" and that he felt "uncomfortable" as a Jew; and a respected former graduate, Dr Andrew Sanezenko, returned his Southampton university degree in protest.

One of the university's major patrons was said to be thinking of withdrawing funding from it, and a solicitor, Mark Lewis, announced he would "look unfavourably" on Southampton graduates applying to his firm.

A delegation of Jewish leaders, including Britain's ambassador to Israel, Mathew Gould, whose inappropriate inclusion should have raised questions about his diplomat's role, met with four university vice-chancellors to discuss the limits of free speech, in clear reference to the Southampton conference.

There are many other examples of this kind of intimidation in the service of Israel. Last year the editor of one of the most respected medical journals in the world, the Lancet, Richard Horton, was made the object of a sustained smear campaign by pro-Israel groups aiming to oust him from his position. He had helped to establish a Lancet-Palestinian health alliance with Ramallah's Bir Zeit University in 2013 to enable Palestinian health workers living under Israeli occupation to publish their research in the journal.

Horton's support for these medical professionals was branded anti-Israel bias, made worse when the Lancet published a letter last July during Israel's war on Gaza signed by 24 leading physicians and scientists supporting Gaza's people and denouncing Israel's attacks on them. The Daily Telegraph headline for September 22, 2014 read: "Lancet hijacked by anti-Israel campaign."

There were demands from the Israeli government for the Lancet letter to be removed, and several Jewish physicians declared they would not submit or review articles for the journal. The Lancet's publisher, Elsevier, was targeted with threats of an intensive boycott campaign against the journal and the large-scale cancellation of subscriptions to it unless Horton was sacked. That has not happened as yet, but it remains a threat.

Cause for alarm

That this formidable array of domestic forces can be assembled so effectively to protect a foreign state, Israel, to the detriment of free speech in a democratic country, should be cause for alarm. The smear of anti-Semitism is the perennial weapon of these pro-Israel lobbyists, and it seems to work every time. That and the real threats to the status and livelihoods of Israel's critics have succeeded in silencing many of them.

The same applies to organisations and institutions. It is past time for this kind of terrorism to be challenged, and in that respect the Southampton conference was an important event. For it would have exposed the shaky foundations on which the Israeli edifice is built and which drives its supporters to ensure that no one finds out.

Israel's "right to exist" is not a taboo subject, and should not be so especially in the context of the cost of its existence to the Palestinian people. No state established on the stolen land and property of another people and their continued oppression has any right to exist.

The best way to end this pro-Israel bullying is to stand up to it, firmly and every time. Southampton University should set a precedent that those in a similar predicament can follow, and reinstate its conference as soon as possible.

Ghada Karmi is a research fellow at the Institute of Arab and Islamic Studies, Exeter University .

The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.