Apols for carrying on with the argument, so to speak:

Jews are people who follow the religion, ergo they can't be zionists

A kind of 'l’impasse' since Kahanists were religious, but turned into zionists. Kahane was a rabbi at the end of the day.

Nevertheless, you clarify:

.. who if they had been Jewish, committed apostasy when they took up zionism, the antithesis of Judaism.

Hence I can understand why you dismiss Kahanism, but you never explain why this is so e.g.

.. the antithesis of Judaism.

Why so?