The testing second stage of Gaza’s ceasefire was always in doubt; now it seems to be dead at the moment it was meant to start.

Concern is mounting that war will return to this ravaged territory, deepening the profound suffering of Palestinians and threatening the lives of the remaining hostages held by Hamas.

Israel, backed by the United States, says there is a new deal now, after the agreement’s first phase ended on Saturday. And it has halted all humanitarian aid to Gaza until Hamas accepts this new version too.

“A flagrant violation,” was Cairo’s strongly worded response. Egypt as well as Qatar, the two Arab mediators in this process along with the US, have also accused Israel of violating international humanitarian law by “using food as a weapon of war”.

Under the terms of the agreement, 600 trucks carrying vital humanitarian aid are meant to enter Gaza daily – and huge numbers crossed through the 42 days of the first phase.

There has also been a loud chorus of criticism from other Arab states, as well as humanitarian leaders.

UN Secretary General António Guterres, who has arrived in Cairo for Tuesday’s emergency Arab summit on rebuilding Gaza, called for the “immediate” resumption of assistance. He urged “all parties to make every effort to prevent a return to hostilities”.

Under the agreement, which came into effect on 19 January, this is the week when Israel should be pulling its troops from the Philadelphi corridor along the Egypt-Gaza border and negotiations should intensify to end the war, return all the remaining hostages, and release more Palestinian prisoners in exchange.

But Israel’s Prime Minister, Benjamin Netanyahu, says US envoy Steve Witkoff has come up with a new plan.

Witkoff has not yet announced his proposal, but Netanyahu said the first stage of the ceasefire would be extended for another 50 days, to cover the Islamic holy month of Ramadan and the Jewish holiday of Passover, and to continue negotiations.

Hamas, in exchange, would immediately release half of the remaining hostages, according to Netanyahu. Israel says 59 are still being held captive and “up to 24” are believed to be alive.

On Monday Hamas denounced this sudden shift as a “a blatant attempt [by Israel] to evade the agreement and avoid entering into negotiations for the second phase”.

The group regards the hostages as its most important leverage and will make every effort hold on to them until this current confrontation ends on terms its willing to accept.

A day earlier, Egypt’s Foreign Minister Badr Abdelatty emphasised: “There is no alternative to the faithful and full implementation by all parties of what was signed last January.”

Israeli media have published reports of an Egyptian proposal for Hamas to release three living hostages and the remains of three others in exchange for a two-week extension of the ceasefire and an Israeli pullout from the Philadelphi corridor, as well as the main north-south Salah-al-Din road.

But an Arab diplomat with knowledge of the talks said they had not resumed yet in Cairo, although “technical teams are in constant discussion”.

There was always going to be a dangerous standoff at this point.

Prime Minister Netanyahu’s primary aim has always been to “destroy” Hamas’s military strength and political grip.

Their highly choreographed ceremonies and show of force during the hostage releases has angered Israelis and underlined that, while it has been significantly weakened, Hamas is still very much in charge in Gaza.

Arab diplomatic sources say that while Hamas has accepted it will not be involved in running Gaza once this war ends, it will not dismantle what is left of its sway.

That is unacceptable to Israel, and to its most important ally, the US.

On Sunday, the US National Security Council gave its full support for Israel’s “next step”. It put the blame firmly on Hamas, saying the group had “indicated it’s no longer interested in a negotiated ceasefire”.

In a video address, Prime Minister Netanyahu described President Donald Trump as “the greatest friend that Israel has ever had in the White House”.

But Israeli media say Washington is also putting pressure on the Israeli leader not to restart the fighting.

That kind of arm twisting is widely acknowledged to have pushed the ceasefire deal over the line even before the Trump team entered the White House on 20 January.

Pressure also mounts from Israelis increasingly anxious to see all the hostages come home.

On Sunday night, hundreds of protesters broke down police barriers outside the prime minister’s residence in Jerusalem.

The US president, praised by his supporters as “the world’s best peacemaker”, could again shape the parameters of war or peace.

In the meantime, both sides are readying to resume the fight while they weigh their options for winning a peace on their terms.