There are three overused and hugely powerful words that I never employ without the clearest contextual evidence: “Nazi”, “fascist” and “tragedy”.

Using them loosely cheapens them, as anybody who lost family in the Holocaust can attest.

The death of my sister’s mother in Auschwitz in 1944 does properly engage all three words, the tragedy being that of a young mother’s life being ended by despicable cruelty. The same cannot be said for much modern usage.

Contemporary extremists of all stripes are cruel demagogues, linguistic vandals and hooligans, best dealt with by rational if sometimes angry argument.

The instruments of legislation and the criminal law should be applied to them vigorously, though without over-defining extremism in ways that dilute proportionate freedom of speech. It is legitimate to be censorious, but not to encourage censorship.

Tragedy includes the Manchester Arena disaster. The recent report by Sir John Saunders demonstrates that many deaths might have been avoided if MI5 had acted differently. That is a tragedy.

So were the recent violent deaths at Epsom College, where I am President of the Royal Medical Foundation. These are tragic incidents that shock us to the core, as events of extreme cruelty devoid of logic.

My three words can come into play when nation states descend into extremism, and abandon the Rule of Law to arbitrary and unpredictable actions.

The Holocaust was just such a situation. Lord Bingham of Cornhill, the great jurist of our times,said: “The rule of law does not require that official or judicial decision-makers should be deprived of all discretion, but it does require that no discretion should be unconstrained so as to be potentially arbitrary. No discretion may be legally unfettered.”

The photographs of dead Ukrainians and Russians following battles in Ukraine illustrates how abandonment of civilised standards, and the misuse of language, can cause major tragedy. Putin and Lavrov have accused the Ukrainians of being fascists, an outrageously false justification for a lawless invasion and countless war crimes.

In Iran, those who are brave enough to demonstrate peacefully against a cruel government are strung up on cranes, or poisoned in their university accommodation. The government behind these actions claims a theological foundation for their rule.

It looks and feels like a form of religious fascism, tragically destroying lives and families. Afghanistan denies education to women — a policy that justifies the fascist label.

What about Israel? Currently it is on a tightrope, with the rule of law on one side and the quicksands of despotism on the other.

I care about Israel. Uncles and aunts and cousins of mine went to live there, and made good lives in freedom. I am as strong a supporter as any of its absolute right to exist, and to exist without constant threat.

One of Israel’s treasures is its Supreme Court, on which now and since 1948 have sat world-class jurists with a unique and imaginatively designed jurisdiction, a jewel in the country’s constitutional settlement.

The keystone of its reputation is the independent system for the appointment of its judges, and their independence from politics. It is the rule of law writ large, the counterpoint to the regime that created the Holocaust and its terrible consequences for many Jews who settled in Israel.

Last Saturday evening, 4.3 per cent of the entire population of Israel protested at the Netanyahu government’s intention to remove the independence of the court — the equivalent of 2.8 million Britons or 14.2 million Americans on the streets.

Benjamin Netanyahu seems deaf to the protesters, who include business people, IDF reservists, teachers and business people. He is now losing the support of Israel’s great ally and guarantor, the US.

The statement by Israel’s current finance minister Bezalel Smotrich that the Palestinian town of Huwara “needs to be erased” (which he has now said he did not mean) was described by US State Department spokesperson Ned Price as “irresponsible… repugnant … disgusting”.

More than 330 synagogues in the USA have said that Smotrich would be unwelcome iwhen he visits the country shortly.

Netanyahu and Smotrich are destroying the reputation of a great democracy by their words and cynical political manoeuvres.

They are threatening the rule of law. Their policies are beginning to look like a terrible tragedy that could bring violence to large parts of the Israeli and Palestinian populations, unless politicians around the world — and above all the diaspora — insist the foolishness must stop.

There are genuine mediators in the western world and in the Middle East, countries dedicated to continuing talks and the quiet development of a credible two-state solution.

There are politicians in Israel and on the West Bank who see a bright future for the region as a political and economic powerhouse, working as neighbours even if it is little more than peaceful coexistence.

Let us all use such influence as we have in that direction, and avoid allowing any of my three least favourite words to be used against the State of Israel.

Lord Carlile KC is a crossbench peer, a barrister and the government’s former independent reviewer of terrorism legislation