As convoys of Israeli tanks and armoured personnel carriers rumbled across wasteland into Gaza on Friday evening, it marked the beginning of a new phase in the war.
Whether it will prove to be the full-scale invasion that Israel has been threatening, or more limited but sustained incursions into the besieged coastal strip, the escalation heightens the risks of a broader conflict.
In Israel, a nation traumatised and enraged by the deadliest single attack in its history, many no doubt will feel it is time to punish those responsible — Hamas, the Islamist militant group that controls Gaza.
On Friday, Israeli officials made clear the objective is to destroy and uproot Hamas and bring a new administration to the enclave.
For the 2.3mn people of Gaza, the intensifying Israeli offensive will bring fear and trepidation. Over the past three weeks, the strip has endured the deadliest Israeli onslaught since Hamas took control of it in 2007.
Israel has been advised by many of its friends to avoid a full-scale invasion of the territory, particularly as more than 200 hostages are still being held by Hamas and the Palestinian civilian death toll is mounting.
The militant group is embedded in Palestinian society and its fighters will have been preparing for a ground offensive for years, hiding in a vast network of tunnels known as the “Gaza Metro” and stocking up on supplies and weapons.
A Hamas official told the Financial Times that the group boasts at least 40,000 fighters. It will be joined in the battle by Palestinian Islamic Jihad, a smaller Islamist faction that is closer to Iran.
Military experts have compared Israel’s task with the huge struggle to drive Isis out of the Iraqi city of Mosul in 2016-17. Unlike Israel’s mission, that offensive was backed by a US-led international coalition with the support of the western and Arab worlds. It took nine months to rid Mosul of Isis.
Even if Israel is able to kill or capture Hamas’s leadership and dismantle the group’s infrastructure, destroying its ideology and the reason for its existence will be altogether harder. Palestinians’ urge to resist Israel’s occupation of the West Bank and blockade of Gaza cannot be defeated militarily, Arab officials warn.
The broader risk for Israel is that another front will open up in the West Bank, run by the internationally supported but weak Palestinian National Authority.
Before the latest war erupted, the West Bank was simmering with tensions and enduring the worst cycle of violence since the second intifada, or Palestinian uprising, ended in 2005 as Israeli forces launched almost daily raids into the territory.
More than 100 Palestinians have been killed in the West Bank since the latest conflict began on October 7, some in clashes with security forces, others in attacks by Jewish settlers, according to Palestinian health officials.
An even more ominous prospect is the opening of wider fronts in the war that drag in the US as well.
For two weeks, there has been a steady escalation of exchanges of fire between Iranian-backed Hizbollah, the powerful Lebanese militant movement, and Israeli forces across Israel’s northern border.
So far the clashes, which have also involved Palestinian militants based in Lebanon, appear contained. But there is a risk that they could escalate into the kind of full-blown conflict Hizbollah and Israel fought for 34 days in 2006.
The risk of a miscalculation that inadvertently takes it to the next stage is weighing heavily on many. Dozens of Hizbollah fighters have already been killed in the border exchanges — and the higher the death toll, the increased likelihood that the group’s leaders will feel they need to intensify their attacks.
If rockets rain on Israel from multiple fronts, its powerful air defence systems could be stretched to the brink.
US officials have publicly expressed alarm that the danger that the Israel-Hamas war will stoke a regional conflagration, warning Iran to “be careful” and deploying additional troops, carrier strike groups and air defence systems to the region.
Washington is also conscious that US troops and personnel in the Middle East could face increasing attacks from Iranian-backed militants in the region, particularly in Iraq and Syria, where there are some 2,500 and 900 American soldiers deployed respectively.
This week the US military struck two facilities in eastern Syria that it identified as linked to Iran-backed militias, following more than a dozen drone and rocket attacks on American forces and bases in Iraq and Syria since October 17. US officials framed the strikes as self-defence, but it was another reminder of the risks of escalation.
The most dangerous scenario is a full-blown war between Hizbollah and Israel that draws in the US, Iran, its proxies and ultimately American troops.
Analysts and diplomats believe that Tehran’s calculation is to remain on the sidelines of the conflict. But if Hizbollah escalate attacks on Israel with Iranian support, the US may feel compelled to join the battle.
Iran-aligned forces could target US shipping or other infrastructure in the Gulf, as they have during previous periods of heightened US-Iran tensions.
It is little wonder that since Hamas’s October 7 atrocities, Arab leaders have been warning that the region is close to the abyss.
