There have been occasions in the past when it has been hard to penetrate the thinking of an Israeli government; the events of yesterday supplied one more. At a time when instability, or potential instability, afflicts almost all its borders, from Sinai in the south to Golan in the north, one might have thought that the last thing Israel needed was any action likely to fan the flames further.
But this will surely be the effect of its decision to kill the head of the military wing of Hamas in Gaza. Israel's intelligence agency Shin Bet warned that this was just the start of a campaign against "those who promote terrorism against Israel". There were even warnings yesterday that this may include a ground invasion of Gaza.
Israel's heightened concern for its own security is understandable. The civil war in Syria, which shows no sign of abating, has brought enormous uncertainty into a situation that, while hardly calm, had been generally stable. With the conflict in Syria having the capacity also to rekindle civil strife in Lebanon, Israel has every reason to strengthen its defences and heighten its vigilance.
But to authorise the sort of pre-emptive action for which Shin Bet openly took responsibility yesterday is dangerous to the point of irresponsibility. Ahmed al-Jabari's death marks a return to the illegal assassinations of old. The immediate response in Gaza was another surge of outrage, presaging a new spiral of violence.
Israel faces a general election in January, and the Prime Minister, Benjamin Netanyahu, last week lost his bet on a Republican victory in the US. If the killing of Mr Jabari – which amounts to a new declaration of war on Hamas – is intended to show not only that Mr Netanyahu intends to play the tried-and-tested security card in his campaign, but also that he will not be pushed around by Washington, the stage is set for a volatile winter. If Mr Netanyahu carries on as he has started, peace in the region is further away than ever.