This has always struck me as obvious but I guess I should spell it out explicitly. Zionism will end about the same way Apartheid ended. So it may be useful to take a look at how Apartheid ended.
There never were hostile conventional, and much less nuclear, forces in Africa capable of marching to Johannesburg or Cape Town and capturing the Apartheid state by force. If Apartheid had not capitulated, there would be no forces hostile forces in Africa capable of doing so even today.
What there was, was a situation where the resources available to sustain Apartheid were declining while those available to oppose it were increasing. Would there ever have come a point where there were more and better organized guns on the anti-Apartheid side than the pro-Apartheid side? Maybe in 100 years. That was the general direction or trend by the time Apartheid ended, but it was a trend that posed no threat of being reached in any near or medium term.
Long before anti-Apartheid forces actually got more bullets than pro-Apartheid forces, the anti-Apartheid forces would have had enough bullets to make the quality of life White South Africans enjoyed unsustainable.
That was the short and medium-term threat that resulted in White South Africans negotiating a relatively graceful end to their Apartheid project.
That is the short and medium-term threat that will result in Jewish Israelis negotiating a relatively graceful end to their Zionist project.
I write this because I often read claims that Israel's current conventional and nuclear weapons superiority over the other countries in its region make it invincible. Nobody cares about Israel's conventional or nuclear weapons. They don't play a role in the function that determines Israel's viability at all.
Anti-Zionist groups will not need more guns that Israel overall to reach the point that they can shoot Israeli passenger airplanes from the sky from their territory. Once that point has been reached, Israel will either have to clear the area of Palestinians, accept that they just are not able to use airplanes the way everyone else in the world can, or negotiate a graceful end to Zionism. Of course, they are going to choose the third option.
The example of shooting down airplanes is just one way that comes to mind that a hostile population with unmet demands can make it impossible for an oppressing population to enjoy a reasonable standard of living. It is really not even a good example, but it illustrates that given resources, which would be very available if the United States did not maintain a US/Zionist colonial structure to deny political power to the people of Egypt, Saudi Arabia, UAE, Jordan, Kuwait and others, there are a lot of ways the Palestinians could it just not worth it for Israel to maintain a necessarily majority Jewish state for its 5.7 million Jews.
This is not even a difficult state to reach. The United States has expended trillions of dollars directly and indirectly preventing the outcome of anti-Zionist forces having the resources necessary to fundamentally disrupt the quality of life of Jewish people in Palestine. If not for that, Zionism would not have lasted even as long as Apartheid did.
So what would happen, really before, but I'll say when Palestinian resistance organizations get even a significant chance of successfully being able to destroy an Israeli airliner with three hundred passengers on it?
Could Israel use its nuclear forces as a deterrent? Can Israel say to Egypt, to an accountable Republic of Arabia, Iran, Lebanon, Syria and/or Iraq that if anyone pays or otherwise helps equip the Palestinians with Chinese, Russian, Ukrainian or French-made anti-aircraft weapons, Israel will mount a nuclear response? Who would believe that threat? The threat just is not credible.
Let's say that despite their threat not being credible, Israel actually carried it out. Let's say Israel kills 10 million Muslims in retaliation for the three hundred Jewish passengers on that airplane. Would that save Israeli lives or cause more Israelis to die? When Israel uses a nuclear weapon on a civilian Arab or Muslim population, it has, at most, a few years left of existence, and it guarantees a huge number of Jewish deaths worldwide.
Nuclear weapons are of no use at all against the real short and medium-term threat against Israel, the threat that White South Africans capitulated to.
What about Israel's conventional weapons? Israel can threaten to occupy more territory to prevent the Palestinians from being armed. Except now Israel is fighting the war it lost in Lebanon in 2006 on more sides and against more and better financed opponents. The civilians it saves from attacks on airplanes it will lose in the form of soldiers carrying out any occupation of the hostile territories around it.
The cost of preventing the Palestinians from emerging as a force capable of disrupting the Jewish way of life in Palestine by conventional military methods ends up being at least almost as high, maybe higher, than the cost of the disruption itself.
The job of the US/Zionist colonial structure is not importantly to prevent anti-Zionist forces from reaching conventional or nuclear parity with Israel. The most important role of the colonial structure is to prevent the people of the colonies of Egypt, Saudi Arabia, UAE, Jordan, Kuwait and others from supporting the Palestinians just as the US citizens support the Jewish Israelis.
Once that structure breaks down, and it is coming apart now, the average person in what is now Saudi Arabia cares a lot more about the Palestinians than the average American does about the Israelis. The Palestinians will have an amount of resources available to them by the cooperation of a government of an independent Republic of Arabia that will be more than enough to impose high daily costs on Jewish Israelis if they choose.
The United States keeps more than 100 million people living under colonial subject dictatorships to prevent that from happening. Its tremendous expenditures in the region, ultimately including the costs of its occupations is for the service of preventing the outcome above. Barack Obama lies when he describes this process as the US' strategic objectives "not being perfectly aligned" with its supposed long term vision.
But when the US becomes unwilling or unable to perform the task of maintaining a US/Zionist colonial structure, a task that violently contradicts the US' founding core values, Zionism will end. It will not end because of a nuclear exchange or because of a defeat of its conventional forces - even though without the US/Zionist colonial structure adversaries of Zionism could, unlike in Southern Africa, very quickly achieve both nuclear and conventional parity with Israel.
Zionism will end because, like in South Africa, the writing will be on the wall, that even though Israel has legacy advantages, the trends will be pointing in a direction that Jewish Israelis will be better off living with a non-Jewish political majority than helplessly watching their adversaries become more and more able to disrupt their way of life.