A storm lashed Israel last week. As rain poured and lightning crackled, Israel said that a rocket streaked into the leaden skies above Gaza, a weapon that could be provoke another war with Hamas, the militant Palestinian faction that controls the territory.

Amos Yadlin, Israel’s head of military intelligence told a parliamentary committee that the rocket flew 37 miles (60km), a distance that potentially brings the centre of Tel Aviv, Israel’s main city, into the range of Gazan missiles for the first time.

This is more than an incremental development. It extends by almost 50 per cent the range of any missile fired out of Gaza during or since Operation Cast Lead, Israel’s assault on the territory earlier this year that was designed to stop such rocket fire.

For many Israelis this weapon — and the handful of short-range rockets from Gaza that continue to hit Israeli territory each week — is a key reason to try and invalidate the controversial Goldstone Report, which earlier this year concluded that Israel’s Defence Forces committed war crimes during its incursion into the Gaza Strip.

Cast Lead has not stopped the rockets and Israel knows that it may have to go into Gaza in similar force again. It wants to do so without restriction on its use of force.

If Israel can recover the recent weapon from its final resting place in the Mediterranean it will be pored over to fully assess the new level of threat. Israel will look to see if the home-made, fertiliser-based propellant in the crude rockets that Hamas generally uses has been upgraded or improved — or whether this is a new military-grade weapon smuggled in through tunnels dug beneath Gaza’s southern boundary into Egypt.

Its recovery would also help to dispel Hamas claims that no such rocket was fired. Israel says that Hamas had hoped that the storm would hide the test firing.

All of this may not yet be enough to start the next Gaza war but it brings it closer. In the Israeli fields around the Gaza border fence they are preparing for future conflict.

Military balloons carry sensors that peer over the perimeter fence, watchtowers dot the landscape and an army shooting range cracks with the sound of gunfire as soldiers refine their aim. Builders are adding £20,000 blast-proof rooms to houses in the nearby Kfar Aza kibbutz: somewhere to shelter in the 15 seconds between a broadcast warning and the impact of a rocket. Construction of similar safe rooms has been underway for months in nearby Sderot, the nearest significant Israeli town and a major target for Hamas rockets in the past.

A warning system is also being tested in Tel Aviv, but Israel cannot meaningfully protect the millions in and around its largest city with such physical shelters.

Israel will want to choose the time of any future Gaza conflict, particularly as the alternative is the strategically unattractive possibility of fighting three simultaneous conflicts — with Iran to prevent it from developing nuclear weapons, with Iran’s Lebanese ally Hezbollah on its northern border and in Gaza.

The seizure of a weapons ship this week, which Israel says was bringing Iranian weapons to Hezbollah, has emphasised the danger Israel now faces to its north.

Prospects of defusing the Gaza threat through politics appear remote. A direct deal with Hamas is beyond unlikely. The prospect of any rapprochement between Hamas and the Palestinian Authority in the West Bank is only marginally more feasible.

The future for Gaza and its inhabitants, who are effectively trapped, is bleak, but the likelihood of them blaming Hamas rather than Israel for their plight appears fanciful.

To Israeli minds the tenuous thread that prevents this situation unravelling now is a calculation that the Hamas leadership has too much to lose financially and politically by provoking another Israeli assault.

Nonetheless, this is a tinderbox and by the time arguments about the Goldstone Report are growing cold, another war in Gaza may be looming.

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