I think one side-effect of for example the Israel - Palestine conflict is that many/most people feel the urge to take a side and in doing so also introduce a bias into their reasoning that encourages them to excuse behaviour by 'their' side and focus on the evils of the other side's actions. One of the things I have respected about Corbyn is his record of sympathising with the side that's often getting the thin end of the wedge, the 'unpopular' side, and he doesn't try to apologise for it like a typical politician wanting to distance themselves from a past opinion that might lose votes for them. Another example - IMO it's absolutely fucking crazy that the UK almost without hesitation invested what will be >£100bn in updating our nuclear weapons stockpile and so did he, even on live TV while getting hammered by the audience for it. It might well be that updating our nuclear weapons program is the right thing to do, but I would want to hear that debate with informed and honest reasoning with regard to the threats the UK faces in this era and how nuclear weapons are relevant in our defence.
I side with Palestine because my understanding is that they're fighting for their lives whereas Israel is fighting for more stuff. I've caught myself barely giving a shit about what Palestine does to Israel largely because of that and partly because of my belief that the winning side of virtually any conflict should bear the greater scrutiny of their tactics. IMO Israel has been fanning the flames of this conflict by cruelly subjugating the Palestinians because it fuels the propaganda for their cause.
I still respect Jeremy Corbyn for the reasons already stated even though I believe he holds anti-Semitic views though if he doubled-down on such nonsense rather than STFU I would be forced to reconsider. As far as I'm concerned everyone makes mistakes because of the bias I mentioned; it's how one reacts to being faced with the effects of that bias is a useful measure of a person.
- edit - I'm going to give further thought to my conclusion because normally I regard not admitting fault as a cowardly way out.
I think one problem with Corbyn is that he was always quite a marginal figure, even on the left, and ended up in that job by accident, because he was the only '80s leftist still around. And he spent most of his career on 'internationalist' issues, opposing 'imperialism' (rather than on economic domestic issues). That's not really much of an asset when you need to get votes from British people, who are often quite nationalistic. As American liberal friends have pointed out when I complain about Biden's American nationalism, you _have_ to buy into that stuff or nobody will vote for you. Corbyn never did, which meant he wasn't a great choice for leader.
I have no idea if he is personally anti-Semitic, there was not much evidence of it, but there is the fact he came from an upper-class background and went to an elite English school, and anti-Semitism is common in that world. And his brother is downright weird (climate-change denier and conspiracy-theorist anti-vaxxer), which makes one wonder about JC by association. And he just never got a grip on the influx of crazy people into the Labour Party under his leadership. Which suggests maybe he just didn't take anti-Semitism seriously enough - but on the other hand there seems to be some evidence that the Labour Right was working hard to ensure the problem didn't get fixed, because it undermined Corbyn.
I don't know what I think about Israel/Palestine. Cowardly on my part, I guess, but it seems to me any opinion I have will be that of a dilettante with no real stake in the issue, when it's a matter of life-and-death for people whose very identity means they are heavily invested on either side (and I know many people, even within my own family, who are fervently supportive of one side or the other - people who tend to get into arguments about it if ever in the same room together).