Israel has delivered a proportionate, justified and likely effective strike on Iran’s missile and air-defense systems. This has forced a further dilemma onto Supreme Leader Ayatollah Ali Khamenei, as he tries to maintain deterrence without starting a wider regional war he can’t afford, and whose consequences neither side would be able to predict or control. However, the danger of such an escalation is far from over.

As with the barrage of Iranian ballistic missiles to which Israel was responding, we are unlikely to know the precise impact of Saturday morning’s attack for some days, if at all. Yet this was a combined set of ballistic missile and combat aircraft strikes that Iranian air defenses are unlikely to have done much to block. Tehran’s “nothing to see here” response should be taken as a sign that there were no widespread civilian casualties and that Khamenei wants the option to deescalate.

All of this should be welcomed. The drive within Israel to end for good a concerted, Iranian-backed attack on the Jewish state since last year’s Hamas atrocities is palpable. This could have been a far more ambitious assault. Israel could have seized the opportunity to damage Iran’s energy infrastructure and nuclear fuel program, leaving the regime with no option but to respond in kind, not just against Israel but the energy interests of the U.S. and its Arab Gulf allies.

There are at least three reasons to be thankful that isn’t the war that everyone woke up to, and to start looking for ways to ensure that its arrival hasn’t just been delayed until some future round of escalatory attacks between two military powers that have the capabilities to do horrific damage to each other and the wider region.

The first is that Israel’s search for absolute security isn’t achievable and the attempt would likely prove counterproductive over the longer term. Israel has killed Yahya Sinwar, the architect of Hamas’ savagery last year; it has decapitated Hezbollah in Lebanon, severely degrading the offensive capabilities of Khamenei’s so-called Axis of Resistance; and it has humbled Iran itself. These are already huge wins.

What Israel hasn’t done is to attach these military gains to a plausible political strategy. Hamas, a deeply rooted and ideologically driven organization, was never likely to crumble and disappear with the killing of its leaders — among whom Sinwar was only the most recent casualty. Its potential for further Oct. 7-style invasions (achievable even at the organization’s peak only due to profound Israeli intelligence and security failures) is gone. The Israel Defense Forces are currently clearing northern Gaza of its population as Hamas fighters, inevitably, emerged to regroup.

Emptying territory of its Palestinian population is, without question, the most certain way of eliminating Hamas from Gaza — but only if the evacuation is permanent. To do so would meet any definition of ethnic cleansing, which sadly is what Hamas and Iran intend for Israel and more common than we like to think in our histories. It is also, rightly, a war crime and what the international community prevented Serbia from achieving in Croatia, Bosnia and Kosovo during the Yugoslav wars of the 1990s.

If Israel is not to be guilty in fact of the crime it already stands accused of committing, Palestinian civilians will have to be able to return home, and to more than rubble. Israel would then need to cooperate in enabling Palestinians to have a new and credible leadership and future that makes Hamas’ grotesque ideology and violence redundant. The alternative is an indefinite, vicious and unstable occupation.

Something similar is true in Lebanon. There, the IDF can no doubt in time drive Hezbollah back from Israel’s border, but without some form of a wider political deal, that would leave Israel — not for the first time — in a state of indefinite occupation and war. Nor would Israel’s northern towns be made safe, as many of Hezbollah’s missiles would still be able to reach them. The likelihood that Iran is again drawn into attacking the Jewish state, triggering a new round of escalation, would remain high.

It’s true but facile to say Israel is already at war with Iran. The two countries have been engaged in a low-level conflict for many years, but its ill effects for the civilian populations of both countries were limited. Hamas changed the rules of engagement on Oct. 7, and now for the first time, both sides have publicly owned direct conventional strikes against the other. Both have shown they have the capacity to break through air defenses. An open war would involve massive destruction, economic loss and civilian suffering.

Perhaps the greatest cause for concern is that Israel’s actions reverberate in an increasingly fraught geopolitical context. Iran is no longer isolated internationally, but is backed by Russia, both militarily and diplomatically. Moscow, in turn, is now getting direct military aid from Iran, as well as from North Korea, and less direct but equally important help from China. Yemen’s Houthis, meanwhile, have reportedly moved missile-capable units to southern Syria. Nobody can predict with any confidence where a full-scale war between Israel and Iran would lead.

Israel already has exacted a very high price from Hamas for the horrors of Oct. 7. It has done the same to Hezbollah for attacks it began a day later and has delivered a harsh reality check to Iran’s trigger-happy clerics. Yet the civilian cost of the war in Gaza has become unacceptable, doing significant damage to the Western bedrock of support for Israel, even in the U.S. The continued refusal to make clear what Israel’s long-term intentions are, both for the Palestinians of Gaza and the West Bank, threatens to make that damage permanent.

Terrorist organizations like Hamas and Hezbollah thrive on repression and chaos, as does Iran’s revisionist regime. Complex, wealthy democracies such as Israel’s don’t. It’s past time for Iran to accept the failure and cost of its aggressive attempts to throttle and destabilize Israel, by de-escalating itself and reining in its attack dogs. There is, after all, a ready peace to be had in Lebanon; all Hezbollah has to do is agree to implement the UN resolutions it agreed to in 2006, pull back to from Israel’s border and muzzle its guns. It’s also time for Israel to take the win. The alternative is a regional war that will bring nobody security or prosperity, including Israel.

Marc Champion is a Bloomberg Opinion columnist covering Europe, Russia and the Middle East. He was previously Istanbul bureau chief for the Wall Street Journal.