It's an interlinked ecosystem.
The war with Iran is Israel's response to a) Iran's incessant threats over the decades to expunge the Jewish state from the fate of the earth, b) Iran's efforts to develop long-range missiles and a nuclear arsenal and c) Iran's decades of sponsoring anti-Israel and outright antisemitic actors in the region (Hamas, Hezbollah, the Houthis - an evil trinity if ever there was one).
To go back a step, Israel was attacked in October 2023 by Hamas-led militants who broke through the border and carried out a pogrom of a type not seen since the Holocaust, culminating in carrying 250 hostages into Gaza (where 85 of them were killed).
The response to that pogrom in the West was quite incredible to many people. Even before the pogrom had finished, even before Israel had responded with an attack on Gaza, pro-Palestine organisations were planning a march, and these marches took place every week for months. During them, and in public discourse and journalism, Israel was routinely monstered:
Accused of genocide when the ratio of civilian: combatant deaths was one of the lowest on record, if not the lowest, despite the fact that Egypt closed its border against refugees (an over-looked little detail) and despite the other awkward fact that Hamas had used concrete coming into Gaza over the decades to build terror tunnels, but no bomb shelters for the civilian population;
Accused of doing things it didn't do, like hitting the Al-Aqli hospital (just one example of bias by the BBC);
Accused of being a white settler colonial state, despite the fact that most Israelis aren't, in fact, white, and the other fact that many Jews entered the country as refugees from Arab states that had driven them out;
Focused on Israel/Gaza to the almost complete exclusion of other awful things going on in the world - the persecution and murder of Christians in northern Nigeria, for example, or of those in the Sudan.
And so on.
ALL of that has fed into the current atmosphere in the UK. Yes, it's quite possible that if it turns out to be an Iranian cell that firebombed the ambulances and damaged the nearby synagogue, this is something that they would have done anyway - but this act tells you that it's not just Israel that Iran has a problem with, it's Jews anywhere.
And the response to that firebombing has everything to do with latent and not-so-latent antisemitism becoming more open as a direct result of those marches and the skewed reporting. We can see it all over this thread: 'But Gaza!!'
FWIW, yes, Israel has at times done bad things. Yes, I know the roots of this conflict go back for a century or more. I also know that the Palestinians have turned down the offer of a state on several occasions. They could have made a functional state in Gaza, but they voted in Hamas.
I'm not Jewish, but I lived for a time in north London. I got to know a Jewish family very well, though we have since lost touch. Their synagogue was Machzike Hadath, the one that had its windows blown out. This feels very close, and I cannot tell you how much I despise the men that carried out the attack.