An astute friend recently observed that today’s crisis in the Middle East boils down to one question about two dates: Which historic moment is likelier to be reversed: 1948 or 1979?

The dates are references to the creation of the state of Israel and, 31 years later, the Iranian revolution. The implication of the question is that it’s one or the other: The Jewish state and the Islamic republic cannot permanently coexist, at least so long as the latter seeks to destroy the former. Recent days have brought two potential vehicles for their downfall into focus.

There was, first, the announcement from Karim Khan, the International Criminal Court’s prosecutor, that he would apply for arrest warrants against Prime Minister Benjamin Netanyahu and Defense Minister Yoav Gallant of Israel.

The decision is unlikely to ever lead to any arrests, much less to criminal convictions: The Biden administration has already denounced the decision, and even countries less friendly to Israel are unlikely to arrest the leader of a nation with nuclear weapons and a powerful intelligence agency.

But the announcement forms part of the same broad strategy that Israel’s adversaries believe will ultimately be the downfall of the state: international delegitimization and isolation, leading to gradual internal collapse or external conquest. Even Khan’s decision to seek the arrest of three Hamas leaders along with Netanyahu and Gallant is of a piece with the overall strategy, as it places Israel’s leaders on a moral par with a trio of terrorists.

Then there was the death on Sunday of Iran’s president, Ebrahim Raisi, along with the foreign minister, Hossein Amir Abdollahian, and six other people apparently by accident — “apparently” because the possibility that the helicopter they were in was brought down by foreign or domestic saboteurs can’t be fully ruled out.

But whatever caused the crash, it both betrays and portends weakness for the regime.

Betrays, because competent states should be able to fly V.I.P. aircraft without incident (the notable exception being the plane crash that killed President Lech Kaczynski of Poland and 95 others in 2010). And portends, because Raisi, an ultrahard-liner who cut his teeth as a prosecutor in the 1980s sending thousands of prisoners to the gallows, was widely seen as a successor to Iran’s 85-year-old supreme leader, Ayatollah Ali Khamenei.

Now the country must, within 50 days, hold elections that will underscore the deep unpopularity of the regime: Voter turnout has been falling for years as Khamenei restricts the electoral slate to all but the most hard-line candidates. It also sets the stage for a power struggle to succeed him, particularly given the wide reluctance to hand the job to Khamenei’s unpopular son, Mojtaba, effectively turning the regime into the type of monarchy it sought to replace.

Add to this mix a deep economic crisis — the Iranian rial now trades at about 577,000 to the dollar on the unregulated market — along with lingering fury over the brutal suppression of the 2022 protests, and the potential for severe instability or abrupt regime collapse is real.

The single most serious risk to Israel, as the former Iranian president Akbar Rafsanjani once put it, is that: “The use of even one nuclear bomb inside Israel will destroy everything, however it would only harm the Islamic world. It is not irrational to contemplate such an eventuality.” Iran’s expanding nuclear capabilities (and its opacity about them) should alarm the Western world a lot more than apparently it does.

But the danger to Israel from moves at the I.C.C. — or, for that matter, from campus protests, boycott and divestment efforts or various kinds of arms embargoes — are minimal. Contrary to some opinions, Israelis are not “settler-colonialists.” Jews believe they are originally from the land of Israel because they are. And Zionism, far from being a colonialist project, is the oldest anticolonialist struggle in history, starting during the Roman era, if not the Babylonian Captivity before it.

As for the idea that Israeli Jews should return, like the Algerian French pieds-noirs, to the lands of their forebears — where, and what, is that? The lands of Russian pogroms, or Arab massacres, or the Holocaust? Israel’s harshest critics tend to miss the point, but Israelis don’t: They have nowhere else to go, a fact underscored by the waves of hatred now engulfing Jewish diasporic communities. The more pressure is exerted on Israel to relent in the face of its enemies, the more Zionism it will generate. Nothing so crystallizes Jewish identity as these daily reminders of bigotry.

For Iran, the principal threat to the regime comes from within and below. It is easy to forget that before the 2022 mass protests over headscarves and women’s rights more broadly, there was the 2019 mass protests over the price of fuel and the 2018 protests over economic conditions. Or that, 10 years earlier, there was the 2009 Green Revolution over the stolen election, or the Iranian student protests of 1999.

Though the regime has proved adept at suppressing dissent through ultraviolent means — my colleague Nick Kristof has written powerfully about the use of mass rape as a means of suppressing opposition (something that somehow failed to generate much outrage at places like Columbia or Berkeley) — the increasing frequency and durability of these protests should tell us something.

Two things, in fact: The stock of public anger at the regime keeps rising as the bases of its support keep dwindling. With the death of Raisi, that dwindling base may, at the same time, be dividing. An informal law of economics, named for the late Herbert Stein, holds that “trends that can’t continue won’t.” It should be a law for political survival, too.

Like Iran, Israel still has profound domestic vulnerabilities, only some of which came to the fore in the months of protest over judicial reform that preceded Oct. 7. That’s to say nothing about right-wing extremism, the resistance of the ultra-Orthodox to fulfill their civic obligations or the ultimate question of an eventual Palestinian state. But none of those need put the deepest convictions of Zionism at stake: that Jews have the right to rule themselves as a sovereign state in their original homeland.

For Iran’s rulers, the risks are graver. They’ve always claimed to be the vanguard of an Islamic revolution, but they seem to have forgotten that revolutions have a history of consuming their own. Iran’s people, by and large, don’t want to be Islamists. But Israel wants, and will fight, to remain itself.