Gurgen I get what you're saying, strip away the ideology of Israel's "right to exist" and "right to defend itself" and you're left with nothing but naked power and its material organisation.
The thing is—and I'll try to say this with adequate sensitivity because I sometimes remember you write about these things from a deeply personal perspective, and I respect that—the organisation of power is subject to continuous historical change.
So the dilemma is not whether "is" trumps "ought", but whether to take up the idea of "work as if you live in the early days of a better world" or "work as if you live in the relentless days of a world that will never be better".
According to my values, it's still worth it if people around the world of good faith grapple with the problem of historical change happening for the better. For all people and all peoples, I mean.
After the moment of the 90s marked by the (equally ideological) illusion of the "end of history", we should confront the possibility the 21st century can be every bit as scarred as the 20th century by the sorts of grand scale historical trauma—whether of Jews in Europe, or Armenians in Turkey, or many other systematic atrocities, including those of Iran's theocracy and its allies in the Middle East—which is contributing right now to the mass-political emotions that rationalise mass deaths in Gaza, Ukraine and other places.
There are some foreseeable ways in which things go really badly, go even worse than they have before, and we can do what incremental things we can to try to stop it from happening. One place that starts for me is with stopping civilian massacres and dismantling the ideas that foster them, which to me have included German, Turkish and Israeli ethnonationalism, as well as Islamic fundamentalism, as well as "strategic interests".
In whatever good faith I can still muster about it, I can't accept the line from Germany, implicitly continued by the diplomatic half-efforts of the allies of US and NATO hegemony around the world, that "Israel is doing everyone's dirty work" by pivoting from slaughtering Palestinians to escalating to regional warfare. It can't readily be accepted this helps us to dodge the outcome of a worse, not better world—no more than it can that Putin has by invading Ukraine via the logic of the "strategic interests" of "great powers" mounted by all sides of inter-imperial struggle.
If this is what the declining relative might of the United States and Europe has to offer an unadorned vision of "united nations" … we all need something different.