Israel has an unquestionable right to defend itself, but it must be wary of triggering a wider conflict

Even at this stage, the world may not have fully grasped the portent of Israel’s prime minister, Benjamin Netanyahu, using the word “war” about the attacks on Israel by Hamas forces. He did not use the adjective “total” – but he hardly needed to.

The imposition of a “complete siege” on Gaza by the Israel Defence Forces should assist in focusing minds in the region and far beyond. It will be harsh, but, as Mr Netanyahu might point out, this is war.

Whatever path Israeli policy follows in the coming days, it should avoid measures that will erode world sympathy for a nation under a barbaric attack. There was no justification for it – but as a civilised nation and a democracy, Israel should keep to the international conventions of war. There is no doubt, though: the outlook is unrelievedly grim.

Israel has the right to defend itself and treat this as an aggressive war. This is more than another intifada, and has the character of an international conflict, albeit an asymmetric one, and one that both sides seem determined to prosecute until exhaustion. The challenge for the international community is to exert whatever pressure and influence that can be brought to bear to at least “quarantine” this war, and prevent it spiralling into a wider conflict in the region.

Many have identified the hand of Iran behind the Hamas strike, and, if so, it comes as no great surprise. Iran is increasingly the most troublesome of regimes, interfering in Ukraine, Iraq and Syria, as well as Lebanon and the occupied Palestinian territories. This raises the global stakes immeasurably – because Israel is an undeclared nuclear power with a considerable military, and Iran is close to perfecting rockets with a thermonuclear payload. It also has sizeable forces and militia allies across the region.

The fact that the US has sent a fleet to the eastern Mediterranean is a reminder of just how seriously the White House views this conflagration. Other regional players – such as Saudi Arabia, Syria, and Russia, too, as well as the militants – will be assessing their own options. Soon, Egypt may be faced with hundreds of thousands of Gazan refugees. The reactions of Hezbollah in southern Lebanon and in the occupied West Bank are awaited with some trepidation. It comes as no surprise that the price of oil, already on the rise, has spiked by 5 per cent over the weekend.

The shock to Israel is obviously profound, and won’t be assuaged. It has been dubbed “Israel’s 9/11”, and has provoked a similar urge for revenge. As an unexpected armed incursion onto Israel territory with barbarous assaults on innocents, it has the combined impact of the Yom Kippur war and the Munich massacre in the early 1970s. It has struck fear deep into the Israeli psyche; fear at the intentions of those around it – and justifiably so in the case of Hamas, which seeks to destroy the state and drive its residents into the sea. For obvious historical reasons, that is something that can only strengthen Israeli determination.

Hamas, we should be clear, is not a normal political entity. It does not seek a “two-state” solution, which remains the most practical resolution of the historic conflict. Rather, as the slogan goes, it seeks a Palestinian state “from the river to the sea”, and all that that implies. Hamas has ruled Gaza without recourse to free elections since 2006, and, aside from its special relationship with Tehran, it is accountable to no one.

During the invasion, Hamas has murdered, injured and terrorised innocent civilians, and taken hostages. It has violated the rules of war and shown the deepest contempt for human rights. It has committed atrocities, of which the massacre at a music festival is the most poignantly egregious.

Mr Netanyahu has a track record of violent retribution, and that process is now well under way. It is, in this context, quite possible to deplore the barbaric attacks on unarmed Israeli citizens in their kibbutzim by militants, while also pitying the unarmed Gazan civilians who are no supporters of Hamas, yet are now to be deprived of water, power, fuel and medicines.

But even wars have rules, and such a move by Israel would place civilians directly in her firing line. It would also be in clear contravention of the Geneva Convention’s rules of engagement. To attack non-military targets, even in retaliation to similar attacks on your own people, would be a red line for the international community.

What does Hamas think it will achieve by confronting Israel? What does Iran hope for from its sponsorship of this nihilistic group? Certainly not any improvement in the condition of the Palestinian people, let alone a lasting peace.

“Invasion” it may have been, but Hamas wasn’t going to occupy Israel and fly its flag over the Knesset. The inevitable Israeli response – massive retaliation, power cuts and, perhaps in time, ground forces – was fully understood and anticipated when Hamas and its Iranian mentors were planning their operation.

Palestinian civilians in their densely populated strip of land will suffer grievously. It is not too cynical to suppose that the joint intention of Hamas and Iran was to create that counter-reaction by Israel, which would provoke a reaction in turn on Israel’s northern and eastern borders and alarm Israel’s friends.

From such a destabilisation of the region, Iran might hope to gain further influence, and at the expense of its traditional rival Saudi Arabia. Indeed, the conflict will further disrupt the negotiations over an historic peace treaty with Israel that the Saudis had been edging towards.

Under the Abraham Accords, the United Arab Emirates, Bahrain, Sudan and Morocco have already recognised and made peace with Israel, just as Egypt and Jordan did decades ago. Although always a long shot, Saudi Arabia joining this “club” fills Iran with some dread. For Hamas, it would be yet another Arab state that has reached its accommodation with Israel at the expense of the Palestinians, and highly unwelcome.

At any rate, the most likely, and tragic, medium-term prospect is of a proxy war between Israel and Iran fought in the rubble of Gaza, should the siege fail. There will be more international sanctions on Iran, but they will only be partially successful – there is a mutual sanctions-busting pact with North Korea and Russia, connived at by China.

The only hope is that the Iranian people, weary of their own subjugation at the hands of the ayatollahs, and their support for armed conflict in Ukraine, and now Gaza, will engineer some regime change of their own in Tehran.

That is where it is needed.