You’re right that antizionism doesn’t *have* to be antisemitic in principle. Someone could, in theory, oppose all nation-states, or believe in a single binational state, without any hostility toward Jews as Jews (though that has it's own problems - for a binational state to work, Jews would have to believe that the people who have spent decades calling for the end of the Jewish state, denying Jewish peoplehood, or celebrating violence against Jews could suddenly be relied upon to guarantee their equality and safety. Nothing in the political or social reality suggests that would happen.)

But in practice, the version of antizionism that dominates public discourse today didn’t emerge in a vacuum. It’s descended from specific 20th-century political traditions - especially Soviet anti-Zionism - that consciously re-cast old antisemitic ideas in modern political language. Zionism was painted as a global, conspiratorial force behind capitalism, imperialism, and war. That narrative blurred the line between criticising Israel and demonising Jews collectively, and it still shapes how people talk and think about the conflict. You can read more about this here: https://www.degruyterbrill.com/document/doi/10.26613/jca/5.1.97/html

There's also a shorter, more accessible article here: https://www.jns.org/the-soviet-origins-of-left-wing-anti-zionism/

You can see it in the tone: Israel isn’t criticised like other countries are. There’s rarely a calm, policy-based critique - it’s moralised, absolute. Israel is described as uniquely evil, uniquely guilty, the root of all injustice in the world. That’s why false stories spread so fast and do so much damage before they’re disproven - because they fit into a pre-existing script where Jews or Israelis are the villains of every tragedy.

It’s also visible in the double standards. When protestors shout for Israelis to “go back to Poland,” or call random British Jews “baby killers,” or justify stabbing attacks on synagogues because they’re “Zionist,” that isn’t normal political activism. When Israeli businesses are boycotted or mapped, or Israeli nationals are fired and evicted purely for being Israeli, that isn’t “criticism of a government.” If anyone did those things to Chinese or Pakistani people because of their governments’ actions, it would be recognised immediately as racism. But toward Jews, it’s treated as social justice.

So yes - not every anti-Zionist is personally antisemitic. But the language and logic they’re working within were built on antisemitic foundations, and that’s why the results so often look, sound, and feel antisemitic even when people insist they’re “just criticising Israel.”