This most middle-class of maladies is widespread in respectable circles. It has flared up very badly in Britain during the past week, with some of the most prominent carriers seeking to keep an Israeli theatre company off this sceptred isle.
Habima, Israel's national theatre company, is due to perform at the World Shakespeare Festival at London's famous Globe Theatre. Theatre troupes from every corner of the earth will be there, including from the new nation of South Sudan (whose actors will perform Cymbeline in Juba Arabic) and from New Zealand (in the first Maori-language performance of Troilus and Cressida). Some authoritarian states are involved, too, including China and Zimbabwe.
But it is Habima's involvement, and Habima's involvement alone, that has riled Britain's luvvies and liberals. In a letter to The Guardian, actress Emma Thompson and others said they were "dismayed" at the inclusion of Habima in this global festival. Apparently, by inviting Habima, the Globe is "associating itself with policies of exclusion practised by the Israeli state".
That is, it is infecting itself with the Israeli toxin; it is failing in its duty to keep itself clean of any contact with Israel and Israeli artists, as every member of decent society apparently must now do.
This extraordinary (and thankfully failed) attempt to ban a theatre company from a global festival follows on from last year's ugly interruption of the Israel Philharmonic Orchestra at the Proms, an eight-week season of classical music that takes place at the Royal Albert Hall every summer. Musicians from across the world take part. But when the influential Israel-bashers heard that an orchestra from that country was taking part, their hives started to itch.
And so these "philistines for Palestine" (as an editorial in The Australian labelled them) jeered and shouted "shame" as the orchestra started to play. Watch the video on YouTube. It's a truly depressing spectacle, as the orchestra's solo violinist tries to make his music heard above the din of those who think that nothing Israeli should be seen or heard in polite society.
These censorious attacks on Israel's art fit neatly with broader campaigns to boycott its academics and produce.
Across the West, anti-Israel agitators demand that universities refuse to have any dealings with their Israeli counterparts while right-on shoppers make a virtue of the fact they never buy Israeli oranges or coffee.
There's something very ugly in this PC loathing of everything Israeli-made. You don't have to look far into the historical records, certainly here in Europe, to see that nothing good comes from the boycotting of shops run by "those people" or the attempted ghetto-isation of their culture and practices. Surely Britain's anti-Israel luvvies have at least watched Roman Polanski's The Pianist, the Holocaust-based tale of a man deprived of his true love - making music - because of what he is?
Of course the drowning out of Israeli music at the Royal Albert Hall and the attempted exclusion of an Israeli theatre company from the Globe are nothing like putting Jews into a real, walled-off ghetto. But all involve a process of ghetto-isation, a process of marginalising people on the basis of their origins.
The aversion to all things Israeli has gone way beyond a normal political boycott. The obsession with avoiding Israeli stuff has nothing in common with the positive boycotts carried out by political radicals in the past, whether it was suffragettes boycotting Britain's 1911 census or blacks in the American south boycotting buses with segregationist seating.
Rather, the avoidance of Israel and all its ideas and wares has become a weird way of life for some people, where the aim isn't to achieve tangible political goals but rather an inner sensation of super moral smugness.
Hating Israel is no longer a serious political stance so much as a cultural signifier. It's one of the key ways through which the chattering classes now advertise their decency, their caring streak, their loathing of "evil" and their pity for "victims".
And therefore, the more conspicuous they can make their loathing of Israel, the more loudly and colourfully they can declare it, the better. That is why they constantly write letters to newspapers, tell everyone that they studiously avoid Israeli shops, and wear the Yasser Arafat-inspired keffiyeh - because these are all signifiers of moral worth and thus must be made visible to all and sundry.
Hating Israel is now like wearing a red ribbon for AIDS or making a virtue of eating only organic foodstuffs.
Its consequences, however, are far more dire than donning a ribbon. For the end result of all these self-serving anti-Israel antics is that one tiny country is singled out for chattering-class opprobrium and in the process is transformed into a pariah state. These anti-Israel activists claim to be concerned that Israel is becoming an apartheid state, yet they themselves practice cultural apartheid against Israel.
Habima has come in for some flak in Israel, too, because at the Globe's festival it is planning to perform what some consider to be Shakespeare's anti-Semitic play, The Merchant of Venice.
Yet that play also contains a profound plea for tolerance that the anti-Israel lobby would do well to heed: "Hath not a Jew eyes? If you prick us, do we not bleed? If you tickle us, do we not laugh? If you poison us, do we not die?"