Yes, it is. The entire international community, with the exception of the US and Israel (and occasionally Canada) agrees on this.

It is against international law to claim or obtain territory through war/conquest. And certainly through the ongoing settler terrorism that Israel has been funding and supporting for decades.

And yes, It is obviously, trivially untenable (not to mention racist) for a country to enforce the maintenance of a demographic majority forever. Maintaining a Jewish majority in Israel cannot be achieved without increasingly racist and genocidal policies. This is the reality of the Arab policy, not what it should be, but what it is. And anybody claiming different is either lying or living a fantasy world.

Look at the panic in some quarters of the US over demographic change. What do you suggest is done about it? Is there any way, other than racist or genocidal policies, to prevent brown people and white people from mixing and having brown babies? No.

Demographic control is functionally the same as eugenics. There is no benign way to do it. And Israel is trying to stake its entire identity on it. Again, this wasn't too unusual a way of thinking in the late 18/early 1900s. Today, I was foolish enough to hope we'd evolved past that.