Zionism which is the modern successor of traditional Judaism and that movement in Judaism which has the final word amongst the world Jewry and over the rest of us in the whole West to a degree that is so serious that we are actually dying out for that very reason

What is the correctly punctuated version of this sentence?
Zionism, which is the modern successor of traditional Judaism and that movement in Judaism which has the final word amongst the world Jewry and over the rest of us in the whole West to a degree, that is so serious, that we are actually dying out for that very reason.