Afghanistan, like Vietnam, was not an existential threat to the US. It's not really comparable because of this.

It's not comparable because the disparition of Israel would be an existential threat to the u.s. ?

Realpolitik just means acknowledging the political realities of their situation. Political realism.

Without discussing what should be, only how to do it(, and usually without considering the morality of the path taken, only its assumed effectiveness, there're reasons to believe that Machiavel wrote The Prince as a criticism and not a support b.t.w.).
If i remember correctly J.Mearsheimer liked realism for its predictive power.

Guerilla warfare can sometimes be effective, however I do not believe this approach will lead to victory against Israel

Only because Israel's territory isn't populated by palestinians, which is why i mentionned Ukraine, whose annexed/liberated territories aren't anti-russians like in eastern Galicia, perhaps because they believe that Russia is large enough to become a.n 'future continent'/'original culture' by itself, and want to believe in this idea, and/or perhaps for other reasons. But w/e.

For Israel this isn't a fight to colonize, it's a fight to exist. There are many Arab nations that could take in Palestinians, not so for Jews.

They can go in "the first&free world" if that's your argument.
And they're colonizing more territories because it's a fight to exist ?
As this comment pointed out : palestinians are at most a threat in the future, but aren't strong enough currently to be deemed a serious threat, a fight for survival implies an enemy strong enough to kill you, and as you previously recognised, if we're only talking about palestinians, then they're not there( yet).
Israelis were relatively safe all these decades(, compared to their neighbours), and i could only imagine that Palestine's destruction would enhance their security if arabs/muslims accept it and refuse to stand for palestinians, and if israelis stop there, because they would still have to invade/coup such countries as Iran or political movements such as Hezbollah, and would continue as long as they're not accepted.
If you presented Israel's survival as 'a moral argument'/'what should be', which would probably not be "realist" to do so, then i could return the same argument for palestinians, and ask you why you don't support the intifada on these same moral grounds, but you more likely said that to explain their motivation and give an estimation of their strength/resolve.

I believe you are overestimating both international support for Palestine and the military capabilities of most African and South American nations

As you saw afterwards, i wasn't talking of a military fight, but of a.n economic&diplomatic one(, even if coups generally imply a military role, sometimes bloodless but very often not).

most of their Arabic neighbors recognize that making an ally of the United States and the EU is far more strategically valuable than backing this group that wants endless war and seeking unreasonable demands.

Unreasonable because they won't ever win ? Well, who knows ?
I don't see them supporting Israel and abandoning palestinians(, only Morocco's gains would be significant, yet they're still seemingly hesitant), i'll agree that they still have a margin of retaliation/pressure towards the west though, perhaps are they forced to wait for a more opportune time to act or, as you said, have accepted such unconditional loss, not sure that we would have if the roles were reversed. As previously mentioned, they wouldn't win anything by complying, and i don't see clearly the extent of what they'd lose by resisting(, some could include their honor or other immaterial examples).

Hamas launched this attack because Saudi Arabia was about to recognize Israel, after all, and SA is dependent upon the US for security. If they alienate the US they have Iran to contend with.

In my opinion Saudi Arabia has more reasons to be afraid of the u.s.a.&co than of Iran, since, except for the Gulf monarchies, every single one of their neighbours 'has been'/'is being' destroyed : the color revolutions, Mohamed Morsi, Lybia, Sudan, Eritrea, Yemen, Iran, Iraq, Syria, and even Lebanon is in an economic crisis(, and kinda Türkiye as well), you just have to open a map and list every country. If we're going a bit further then we have Afghanistan, Pakistan, Nagorno-Karabakh, almost all countries destroyed by the west, and i haven't counted kurd separatists or the islamic state, it's not a stretch to think that they desire stability, but what a f*cking world, we don't understand that, Ethiopia, Somalia, Kenya, Congo, Chad, Niger, central asian republics, Georgia, ..., these countries seems far away, if the realist choice is just to always follow the strongest regardless of what's right/fair, then i don't want to be a realist.

Russia has its own issues right now and cannot afford another front

Is there a single non-western country more active than them around the world currently ?

Given their behaviors in Chechnya, they do not seem to be sympathetic to Muslims.

As if they didn't lose enough historical territory in 1991, V.Putin's party isn't called United Russia for nothing, of course we(sterners) supported the separatists terrorists(, but hated them when these "orks" fought on the side of Russia&'south-eastern ukrainians' recently).
The first hostage released by Hamas was an israeli who also had a russian nationality, and there were other gestures if this kind of things matter, the timing of the l.g.b.t. ban may perhaps also be linked in some way, i.d.k.(, they also have their own muslim republics in the russian federation, Chechnya is apparently very homophobic, and it's not only inside their borders or in the Middle-East, but in Africa as well), just to say that i wouldn't count on their islamophobia.

If such creatures exist, they haven't weighed in

The (uncaused )Cause is the only being which isn't a creature(, and the only to be the Being), i don't think a direct visible interference would be that desirable, everything would just be solved and there wouldn't be anything else to do, i prefer to feel free, but in any case there's always determinism and God as the Cause for this kind of interrogation.

It would be like humans trying to control ant societies in our backyards, why would we care?

Not sure that despite our imperfection we wouldn't be a part of the All/One, and there's always the law of karma among other laws of our reality, parts of the All do care, and if we look/seek the Greatest we/ants do care.

I hope we get there one day, albeit through secular means.

You didn't wrote that to imply that we should only get there through secular means(, by fighting other paths), but i find interesting that we fight communism and islamism : apart from these two, and royalism, do you know of a single large ideology that survived the colonization and isn't the western one of a constitutional capitalist secular republic ?
I wrote about these communities with their own rules because i feel that we're unfortunately looking for unity at the expense of diversity, instead of looking for a permanent peace in harmony, ensuring both our unity and our diversity, we're not looking towards this direction, and there's even this selfish nationalism saying that it's not our role to help each other, i can't like it, we should aim to live together.