'We're going to see a lot of carnage': Analysts say Israel on verge of perilous push into Gaza

Israel has opened a new phase in its war on blockaded Gaza by expanding ground incursions inside the Palestinian enclave, but analysts warn the aggression is its riskiest in half a century with fallout threatening the whole Middle East.

Thousands of civilians have already been killed in Gaza and Israel since resistance group Hamas launched its shock October 7 blitz. And the United Nations has led warnings that thousands more will be killed as Israel sends troops and tanks farther into Gaza.

That adds to Western anticipations that Lebanon's Hezbollah could open a new front on the Lebanese border.

With Gaza's hospitals and food supplies devastated, Israel's Arab neighbours worry that the images of Palestinian suffering could trigger a pro-Hamas backlash in their own countries.

Israel's Prime Minister Benjamin Netanyahu vowed an "iron fist" treatment of Hamas after its fighters attacked communities across southern Israel. Israel says they killed 1,400 people and took back at least 230 hostages.

Gaza authorities say more than 8,000 people, half of whom are children, have been killed in thousands of Israeli strikes since the start of the war.

Images of the devastation and indiscriminate targeting of civilians have fuelled anger worldwide. Now tens of thousands of Israeli soldiers are waiting on the border for the toughest stage of a war that Netanyahu said would be long and difficult.

"We are going to see a lot of carnage, we are going to see a lot of horrible things," said Edward Djerejian, a former US assistant secretary of state and ambassador to Israel, who bemoaned the lack of a political initiative to end the crisis.

Israel's 'critical moment'

This showdown is Israel's most perilous since the 1973 Arab-Israel war, when it was also taken by surprise, according to Jonathan Rynhold, a specialist on the Israel-Palestine conflict at Bar-Ilan University near Tel Aviv.

He said Israel will have to be ready for major casualties which will be worse if Hezbollah turns its near-daily artillery exchanges with Israel into all-out conflict.

Israeli troops have been given special training for urban warfare in the Palestinian territory's narrow rubble-strewn streets and huge network of Hamas underground tunnels.

"If Israel follows through on the stated aim of destroying Hamas military capabilities in the Gaza Strip and overthrowing its regime, then the scale and length of this war will be much bigger and much longer" than the four previous fightings in Gaza since 2005, the longest of which lasted seven weeks, said Rynhold.

The expansion of ground of operations "will be the critical moment as to whether a second front opens with Hezbollah and that is a higher risk" than in previous wars, he added.

Open conflict with Hezbollah could drag in the United States and would mean Israel having to accept "a scale of destruction that it has never experienced before," Rynhold said.

The United States and the European powers have given Netanyahu strong support while urging him to limit the civilian casualties that fuel Arab anger, and open up Gaza to more humanitarian aid.

US President Joe Biden has sent two aircraft carrier groups to the eastern Mediterranean and warned Hezbollah and others to stay out. But he has also urged Israel to curtail its "rage".

H.A. Hellyer, a security specialist for the Royal United Services Institute in London, said that Israel is not doing enough to head off new war fronts.

"There is a risk of extension of the conflict," he said. "Israel is prioritising revenge and retaliation over all else, as far as we can see from the statements of senior Israeli officials."

Hamas popularity boosted by blitz

Israel has vowed to destroy Hamas but while it may take out the group's leadership, analysts warn it is unlikely to take away its support base.

Khalil Shikaki, director of the Palestinian Center for Policy and Survey Research in Ramallah, said Hamas is "probably a lot more popular today" in the Arab region than before its unprecedented raid on Israel.

Hamas will retain significant influence in Gaza after the war, he predicted.

Israel has not had the public sympathy it expected in Western countries. And with Iran and others watching closely, it faces the risk of pushing itself into a loop of violence that may span over years as it does not step back from relentless attacks on Gaza.

Israel's reputation "depends on its projection of strength, its swagger," said Laura Blumenfeld, a former US State Department adviser on Israel-Palestine negotiations and now a security specialist at Johns Hopkins University.

If the war tarnishes "its sheen of deterrence" it will look "weak" before its rivals and countries that might be considering normalising ties, she added.

Rynhold said: "It is not that Israel will lose but that the price of victory will be very high."