This comment by Trivet says it all:
“This is actually pretty simple. Israel came into existence as a means for the Jewish people to find a safe homeland following the Holocaust (and 14 centuries of Arab antisemtism, I would add). Organisations and people such as those with whom Jeremy Corbyn has shared a platform are committed to the destruction of Israel and – we must therefore assume – the destruction of that place of Jewish safety. The inevitable result of the destruction of Israel would be the slaughter and enforced displacement of millions of Jewish people.
If you support such a movement and such an end result, you are an anti-semite. No ifs, no buts, no maybes. You are. And if you offer support to such people, you are at best offering succour to anti-semitism and at worst an anti-semite yourself.”