So far it’s working in South Africa, for all the problems it had and is having, as well as in what used to be Jugoslavia, and there is a very long History of etnically diverse populations either ending up cohexisting or segregating into separate independent nations without being constantly at war with each other.

I would even go as far as saying that integration (willful or forced) or peaceful separation into two states are far more common situations than an etnostate successfully suppressing a population without ending up murdering or expelling the entirety of the second largest etnicity.

If you look at History, most conquering of land succeeds because the conqueror actually wants the locals to subject to the rule of the elites of said conqueror rather than pushing them all out, so the people of the conquered territory generally end up integrated into the culture of the conquering nation.

The really special thing with Israel is that it’s an etnostate with a core principle that one etnicity is “favoured by God” whilst trying to pass itself as a Democracy, which is also a conqueror in somebody else’s land, so fully integrating people with equal rights from a large different etnicity that live in that conquered land (something which would be real Democracy) would directly go against the core etnostate principl (as those other people are not from the “favoured by God” etnicity) and would even change the way the conqueror is ruled because equal rights for a sizeable majority means equal voting rights.

So over the years the leadership in Israel has threaded a thin line where they integrated only a few of the local etnicity in order to seem Democratic but not enough for them to actually have real power versus the etnic majority, and only did so by giving them second class rights, while at the same times using techniques like outright giving on Israeli nationality with full rights to anybody from the favoured etnicity who are not yet Israelis in order to boost the number of that etnicity in Israel. So a small number of people from the not-favoured etnicity are second class citiziens, whilst the vast majority of them kept entirelly powerless (with not even second class citizenship), not just in the conquered land but also in Israel proper.

IMHO a Democracy as a conquering nation can only ultimatelly live in peace in that situation if the people in the conquered land are integrated into it (so equal citizens with equal votes) or live so far away from the conqueror’s mainland that they can be kept oppressed and their violence does not reach the mainland (and as we’ve seen when the US did things like conquer Iraq, that doesn’t last), and Israel because of being an etnostate can never accept integrating people from a different etnicity and at the same time sits right next to the very people whose land it conquered and which it oppresses because it cannot integrate them and still remain an etnostate.

There are only three ways for there to be Peace in this situation:

• Israel murders or kicks out every single native from the lands it has conquered, which is what they seem to be trying to do.
• Israel stops being an etnostate, which is incredibly unlikely given that the ultra-orthodox vote is growing and predicted to keep growing without end in sight - in fact the trend is for Israel to just become a full-blown Theocracy rather than merelly a “Democratic” etnostate.
• Israel leaves the land it occupies (at minimum, enough land for a viable Palestinian state) and both people self-segregate.

I would say that most outsiders who are not rabidly pro-Israel are aiming for the last one.

dismantling the brutal apartheid regime

No where does that say dismantling Israel.