One of the more elegant ways pro-Israel activists used to be able to confront the absurdities of anti-Israeli activists was by referring to the tolerance and patience that Israel has for its many critics and enemies. An Islamist cleric whose answer to the Jewish Question is straight out of Torquemada? We’ll let him become mayor of an Arab village. A sinister campaign for the economic and cultural boycott of Israel? We’ll let the head campaigner work toward his doctorate at Tel Aviv University, where his oral defence will no doubt be an attack on his own academic viability. Even an Israeli Arab parliamentarian is allowed to sail on a blockade-busting “freedom flotilla” to denounce the very government to which she belongs.

Israeli democracy, in other words, has long been patient with its gadflies, cranks and nudniks who sometimes confuse that democracy with a banana republic. (Ben-Gurion was hinting at national self-definition when he joked about two Jews with three opinions.) Now, however, those doing the confusing are purportedly acting in Israel’s defence, which is deeply problematic for its democracy.

On Monday, the Knesset voted in favour of a bill that would allow citizens to sue anyone recommending a boycott of not only Israel but of West Bank settlements. This is a distinction with a difference. Salam Fayyad, the prime minister of Palestine, has long favoured a boycott of settlement goods, but not Israeli ones, as a way of forcing Israel to distinguish its GDP from its occupation economy. Diplomatically ill-considered though such a policy may be, and however skirted by the Palestinians themselves in practice, Fayyad’s policy was by no means “anti-Semitic” or belligerent in its logic.

But leave that to one side. What this new anti-boycott law amounts to is a codified commandment: “Thou shalt not de-legitimise.” Rather than confront obnoxious or dodgy opinions, which the so-called BDS movement represents, the Knesset would rather ban those opinions altogether. Zionism used to be made of sterner stuff.

Owing to an extremely backward electoral system, Israel is today addled by a unique kind of political dysfunction. The fringe Right, consisting mainly of ultra-religious and hyper-nationalist types, has projected itself disproportionately into the government, causing both uneasy coalitions and all manner of international embarrassments. Enter a settlement construction announcement that coincides with the arrival of the US Vice President; enter also a “loyalty oath” and other suggested encroachments on civil liberties which, unlike this anti-boycott measure, have so far got held up in parliamentary subcommittees.

Culturally, too, the creep of the fringe into the mainstream has had disastrous consequences. The former Sephardic chief rabbi sounding off about gentiles and Arabs is not just a Talmudic concern when you realise that Ovadia Yosef is also the “spiritual head” of Shas, the party that controls Israel’s Interior Ministry. An foreign minister who never blinks would merit critical scrutiny on any occasion, but it is not a compliment that Vladimir Putin sees Avigdor Lieberman as an ideological soulmate. In most democracies, loudmouths get reality series; in Israel, they get portfolios.

In the midst of such dysfunction, Israel has also found that its political destiny is being decided more by The Guardian and Al Jazeera than it is by the prime minister — a fact that Benjamin Netanyahu seems to grasp uneasily. The Arab Spring ferment at the borders and a frosty relationship with the Obama White House have only added to the sense of tetchiness and desperation.

Moshe Dayan once said that Israel hasn’t got a foreign policy, only a defence policy. It clearly now needs a coherent foreign policy. But if it heads down the long slide of speech codes and the criminalisation of political correctness, it’ll need a rethink on its domestic policy, too.