Anti-Semitism is hatred or discrimination of Jews based on their nationality.

No sane person holds anything against Jews, or supports violence against them. Some actual antisemites do, but they are in the tiny minority.

What people mostly stand against is the violence perpetrated by the Israeli army on the land of Palestine.

Israel has all the capacity to defend its citizens; yet Israeli army went way beyond defence or retaliation, into the territory of indiscriminate razing of everyone and everything, women, children, and sick, homes and hospitals. The state of Israel is accountable for enormous amounts of recorded human rights and law of war violations, and that's the key reason nearly all of the international community took the side of defending Palestine. Should Palestine have the capacity and will to do the same to Israelis at the same scale, the international opinion would reverse.

However, as Israel has to gain public support, which is hard to do when you're commiting genocide, the government and its allies (mainly US and UK, both of whom have strategic interests in Israeli expansion) decided to adopt the rhetoric of antisemitism as something that would virtually put you along the lines of Nazis should you try and challenge their notion. No, Nazis were actual antisemites and pursued to eliminate Jews; the international community wants to put an end to the genocide of Palestinian Arabs, while rejecting any hostility directed against Jews.

Wishing to eliminate one nationality to make safer room for the other, as well as "bringing in the correct values" by means of violence is a bloodthirsty and dangerous fantasy historically proven again and again to lead to terrible outcomes while multiplying suffering; yet by some it is understood for the very imagined and unrealistic scenario of falling Israel, but ignored while Palestine is actively razed by a hostile force of a much greater scale, ignoring all international treaties.