What I have seen is a confusion (perhaps intentional) between anti-semitism, and protesting Israel’s behavior since the Hamas attack in October.
Criticizing Israel’s response is not anti-Semitism- it is literally just criticizing the response.
Of course, a lot of criticism of Israel is rooted in antisemitism. But saying all criticism of Israel is antisemitic deflects legitimate criticism, and makes it harder to identify legitimate antisemitism.
Who is saying this? All I've heard are people on one side insisting that people are saying this, sounds like a straw man
1. https://www.congress.gov/118/bills/hres894/BILLS-118hres894i...
This is not the same as being critical of that state, being anti-Israel isn't antisemitic (except when it is, obviously), but nor is it anti-Zionism. Saying Netanyahu should be dragged before the Hague, that the international community should demand an immediate ceasefire or force a two-state solution, that Israel must uphold the right of return: none of these are anti-Zionism, nor antisemitic.
If your position is not that Israel must be destroyed, good, don't call yourself anti-Zionist though. If it is, then yes, that's antisemitic, or the word is meaningless.
Similarly, find another slogan besides "From the river to the sea", because that is, in fact, a call to ethnically cleanse all Jews from Israel. It has meant that since the establishment of Israel, and you don't get to wander in and say it means something different at this point. If you don't mean that, don't say it. Find literally any other way to express yourself.
> [The belief that] the modern State of Israel, and the movement to create a sovereign Jewish state in the region of Palestine—the biblical Land of Israel—was flawed or unjust in some way
This is very different from "Israel must be destroyed".
Similarly, your interpretation of "From the river to the sea" is extreme. It's only really been a scrutinized slogan since Hamas started using it in 2017. Its previous ~60 years of use were consistently about creating a secular, multi-ethnic, democratic state for all the people inside its borders.
There has never been an official Palestinian position calling for the removal of Jews.
If we did take that to be the definition of anti-Zionism, then it seems one could be both a Zionist and an anti-Zionist, if they supported the existence of a Jewish state but didn't approve of the particular way Israel was established.