Sit, breathe in, breathe out, think, strategise - and then, even though I do not in any way shape or form condone the death penalty - use its leading intelligence capabilities to identify the people responsible and take them out using surgical strikes. So: selectively. Without starving and murdering swathes of civilians in the process.
And, yes, they are perfectly capable of implementing this strategy - they used to use it!
And then, it should request the support of the so-called international community to avoid a power vacuum in Gaza without getting embroiled in another bloody direct occupation.
In the somewhat more overarching, strategic sense: they must start working now towards a truly fair resolution to the conflict. A genuine one, not some sort of supposedly "generous" offer that no Palestinian leader would ever politically survive agreeing to because it is designed to look fair to US Americans rather than Palestinians.
And they should do this not because it is the "nice" thing to do, but because it is in their own best strategic interest in the long term! So far, Israel has enjoyed the unbridled support of so-called Western powers because it has been geopolitically expedient for them to offer it. Forget about all that nice, fluffy "but democracy and shared values" talk - the USA, UK & Co. could not possibly care less whether or not Israelis get to hold a Pride parade in Tel Aviv! They care because Israel has been a useful wedge and a proxy in the region, and because it has often been willing to do the dirty work when domestic political opinion would have made it difficult for major powers to do so directly! But we have already been seeing a shift of focus away from the ME and towards issues such as e.g. China in recent years. The ME has already been kind of "low key ignored" for a while. The cold war is over, and the post-cold-war unipolar world order is dying - if it has not already stopped breathing off a ventilator. And therefore, the strategic value of Israel is changing, too - especially if its policies threaten relationships with allies that are gaining in importance or are serving as a distraction.
Long story short: Israel, in its own best interest, ought to negotiate in good faith now - not once it has potentially lost a lot of bargaining power because its value as an ally against China is greatly diminished!
... naturally, all of this would necessitate an Israeli government with actual political legitimacy, that was not on the brink of being ousted by a tidal wave of protests prior to 7 October - and one that does not consist of extreme rightwing ideologues and a self-serving PM who mostly wants to save his own skin at this point.