Is it kosher to boycott Israeli goods? More and more people say yes. And it is becoming more and more difficult to dismiss all of them as anti-semitic. The boycott campaign has gone mainstream and it is beginning to bite.
Thus, President Shimon Peres marked Israel's 64th Independence Day last month by telling the newspaper Maariv: "Israel has been blessed with a lot of talent that manufactures many excellent products.
"In order to export, you need good products, but you also need good relations.
"So why make peace? Because, if Israel's image gets worse, it will begin to suffer boycotts. There is already an artistic boycott against us - they won't let Habimah Theatre enter London - and signs of an undeclared financial boycott are beginning to emerge."
Shimon Peres somewhat overestimates the success of the boycott campaign in relation to the Israeli National Theatre. But he is right to recognise its significance.
The call from actors, directors and writers - including Emma Thompson, Mike Leigh, David Calder, Trevor Griffith and Miriam Margolyes - for the withdrawal of Habimah's invitation to take part in the Globe-to-Globe Shakespeare Festival specified the group's "shameful record of involvement with illegal Israeli settlements in occupied Palestinian territory".
It pointed particularly to Habimah's decision last year to perform in "halls of culture" established in two large illegal settlements on the West Bank: other Israeli theatre professionals had refused to put on shows for the settlers.
Thompson, Leigh, Calder and the rest pointed out that "by inviting Habimah, Shakespeare's Globe is undermining the conscientious Israeli actors and playwrights who have refused to break international law".
This cannot rationally be construed as anti-semitic. (Which is not to say that some Zionists won't try. A few weeks ago, I mentioned in this space that "some of my best friends are anti-Zionist Jews." I have since been told in robust terms that this "took anti-semitism to a new low". Go figure.)
Supporters of Israel might reasonably make a distinction between calling for a boycott of Israel full stop and calling for a boycott of Israel targeted on activities associated with the illegal settlements.
A distinction might reasonably be made between arguing against a welcome for Habimah to London and appealing to the traditional Irish music group Dervish not to play in Israel proper.
However, this is not a distinction which the pro-Israel lobby believes it can afford to make. Zionism - the official ideology of the Israeli state - holds that the Jewish people have an unfettered and literally God-given right to all of the 'Holy Land' - including those small areas recognised in international law as belonging to the indigenous Palestinian people.
Isaiah 43:1-8 takes precedence: "He who created you, Jacob, He who formed you, Israel, Do not fear for I have redeemed you, I have summoned you ... For I am the Lord your God, the Holy One of Israel, your saviour ... I will give people in exchange for you, nations in exchange for your life ... I will bring your children from the east and gather you from the west ... Bring my sons from afar and my daughters from the ends of the earth ... ."
Rather in the way that the Vatican believes that Church law trumps the civil code when it comes to the rape of children, so Zionists believe that the Old Testament overrules international law in relation to the rape of an entire people.
It is because of their implicit - and sometimes explicit - support for Israeli illegality in the "occupied territories" that opponents of boycott now find themselves on the back foot. The World Council of Churches, for example, has declared itself "convinced of the need for an international boycott of goods produced in the illegal Israeli settlements" and for an investment policy designed to "influence businesses linked to the Israeli occupation and its illegal settlements".
On the same day as Shimon Peres's statement in Maariv, the Scottish Trades Union Congress, at its annual conference, supported a range of resolutions, with the focus of debate fixed throughout on the illegal Israeli settlements in occupied Palestinian territory. On April 27, the Co-operative Group - the fifth-biggest UK food retailer - decided that it will "no longer engage with any supplier of produce known to be sourcing from the Israeli settlements".
President Peres is right to be worried.