I don’t have to remind you that the war that started with Hamas’s massacres continues to spread. At time of writing, it directly involves three Iranian terrorist proxies, Hamas, the Houthis and Hezbollah - which also happens to be part of the government of Lebanon - Iran itself, which has now taken to mounting unprovoked airstrikes on Iraq and Pakistan; Britain and the United States, following our decision to punish the Houthis for their attacks on civilian shipping; and, of course, Israel.

The periods leading up to the last two world wars were marked by smaller-scale confrontations in areas which would later become flashpoints for the wider conflagrations: Serbia, Ottoman Turkey and the Austro-Hungarian Empire before August 1914; the Rhineland, Austria and Czechoslovakia before September 1939. I’ve been asking myself whether future historians will come to consider events in the Middle East and Central Asia since October 7 as the prelude to another Great War, which given recent advances in lethal weaponry, would be likely to plunge us all into something even worse than its predecessors.

However, I’ll leave that question for another day. The purpose of this column is to consider something rather different to anything that took place in the period before WW1 or during the 1930s: the fact that as the current conflict ramifies, the rhetoric of those living in Britain who back the West’s enemies gets ever more extreme - and continues to attract support from left-wing Labour MPs.

At the anti-Israel demonstration held in London last weekend by the Palestine Solidarity Campaign, both these phenomena were on prominent display. For - so far as I know - the first time on British soil, some protesters openly chanted in favour of the Houthis, a terrorist militia that have launched missiles against shipping, plunged Yemen into poverty and chaos, caused countless civilian deaths, persecuted the Baha’i minority, reintroduced slavery and stands accused of war crimes.

But in the anti-imperialist eyes of some at the PSC protest, if the Houthis don’t care for the West, they must be the good guys, and so the chant went up: “Yemen, Yemen, make us proud, turn another ship around.”

Placards carried by many of the marchers were equally extreme. “Thank you, Yemen” read one, the words decorated with love hearts. “Beware the deadly virus, Israel”, said another, adornedwith the red triangle which has become a signal of support for Hamas. Some carried pictures of the terrorist Leila Khaled, others bore images of the Israeli ambassador Tzipi Hotovely to which red devil’s horns had been added.

One 30ft wide banner carried the slogan “Victory to the resistance! Resistance to Israeli occupation is a right and a duty”; another, “The world stopped Nazism. The world stopped apartheid. The world must stop Zionism.” There were also balloons with the legend “Burn the IDF to ash.”

After the march, speakers from a platform in Parliament Square included Mohammed el-Kurd, a Palestinian writer. “We must reject Zionism in all of our institutions, because to be anti-racist is to be anti-Zionist,” he said. “Zionism is apartheid, it is genocide, it is murder… it is a political ideology rooted in settler expansion and we must root it out of our world. We must de-Zionise, because Zionism is a death cult, Zionism is indefensible.”

Yes, you read that right, he said “root it out of our world”. And he and his allies accuse Israel of trying to perpetrate genocide.

At the front of the march, flanked by the Palestinian activist Adnan Hmidan, who once declared his “love” for Hamas’s founder, Sheikh Ahmed Yassin, was one Jeremy Corbyn. No surprises there, and at least we can be confident he will never stand again as a Labour Party candidate. The dark era of his leadership has been consigned to the past.

However, also marching were Corbyn’s deputy leader, John McDonnell, who is still the MP for Hayes and Harlington, and Streatham’s Bell Ribeiro-Addy. Claudia Webbe from Leicester East accompanied them though, like Corbyn, she has been deprived of the Labour whip after she was convicted of harassment. Two serving Labour MPs spoke from the platform they shared with el-Kurd: Zarah Sultana (Coventry South) and Apsana Begum (Poplar and Limehouse), as did Corbyn. In her speech, Begum called the British and American airstrikes against the Houthis “shameful and deplorable”.

I’m pretty sure that the Labour Party leadership is well aware of these MPs’ presence, not only last weekend, but at previous events where the discourse has been only a little less extreme. Press reports show that Begum has attended at least five PSC protests since October 7, McDonnell eight, Ribeiro-Addy four and Sultana two. Other supporters have included the Leeds MP Richard Burgon (three PSC events) and Cynon Valley’s Beth Winter (four).

The question is: as we approach a general election, does the party intend to do anything about it?

The party’s National Executive Committee is controlled by Keir Starmer and his allies, and has already voted to block Corbyn’s return as a Labour candidate. Under the party’s rules, it could do the same for Sultana, Begum, McDonnell, Ribeiro-Addy and, perhaps, others.

I can see good reasons why the leadership might not have the stomach for this particular fight. To excise Corbyn was one thing, to remove four or more of his staunchest cohorts quite another, inviting a torrent of “Labour split” headlines at a politically critical time. In any event, the issue of Hackney North’s Diane Abbott, suspended from the whip for her claim that Jews do not face racism, still has to be finally resolved.

On the other hand, it would demonstrate once and for all just how far Starmer is prepared to go when he speaks of his determination to eradicate Labour antisemitism. I’ve argued numerous times that his intentions are utterly sincere, and the progress he has made impressive. But to me, joining a protest where a platform speaker says it is Zionism, as opposed to antisemitism, that must be “rooted out”, and where marchers proclaim allegiance to a brutal terrorist militia responsible for hundreds of thousands of deaths, crosses an indelible red line. I hope the Labour leadership acts.