The latest outbreak of violence between the Israelis and Gaza's militants is putting Egypt's relations with Israel to their severest test in the 44 years since the former enemies signed a historic peace treaty.
After years of what had become known as a “cold peace”, the two sides have forged relatively close ties in the past decade, co-operating on counter-terrorism, energy and the fight against human and drug trafficking into Israel.
But that spirit of co-operation appears to have been shattered by the violence sparked by a deadly incursion into southern Israel by Gaza-based Hamas militants on October 7, which left 1,300 Israelis dead. More than 2,200 Palestinians have also died in Gaza in retaliatory Israeli air strikes.
Ominously, differences between the two neighbours this time round are fundamental and centre on a host of thorny issues. Should relations experience a permanent rupture, the ramifications for Egypt, Israel, the region and beyond would be incalculable.
Equally worrisome is that Egypt's vital ties with the US – its main economic backer for decades and Israel's closest ally – could be in serious jeopardy if there is a complete breakdown in relations with the Israelis.
None of this should be surprising.
The 1979 peace treaty was the first between an Arab nation and Israel. It ended an enmity that dated back to 1948 when the pair fought the first of four, full-fledged wars.
The treaty also enshrined a seismic shift in Egypt's foreign alliance that reshaped the region's landscape, replacing the Soviet Union with the US as Cairo's main foreign backer and benefactor.
To reward Egypt for making peace with Israel, the US launched a generous aid programme that has seen billions of dollars pouring into the country in economic and military assistance to this day.
But Egypt-Israel relations have deteriorated sharply as Israeli air strikes have in the past week targeted Gaza's border crossing with Egypt at least three times, also causing damage to the Egyptian side of the boundary. Egypt criticised Israel for the strikes and demanded they stop.
Confirming the Israeli position, military spokesman Rear Admiral Daniel Hagari told a media briefing on Saturday that “the borders are closed, and any movement or crossing to Egypt will be in co-ordination with us and in contact with us. For now, this issue is not happening.”
Unfortunately for Egypt, the crisis it faces over relations with Israel and the western pressure it is enduring to adopt policies more aligned with Israel's on Gaza have come amid a severe economic crisis.
“We understand there have been offers to Egypt by some western governments for debt forgiveness and direct investment in return for a more flexible position on Gaza,” said a senior Cairo-based banker, who did not want to be named because of the topic's sensitivity.
Egypt remains steadfast, still loyal to a Palestinian cause it has championed for more than 70 years.
Underlining the rift, Egyptian President Abdel Fattah El Sisi did not mince his words when he indirectly criticised Israel's reaction to the Hamas attack.
Referring to Israeli policies, he said Egypt wanted to see an end to “collective punishment, siege, starving people and eviction”. He warned that “hosting our Palestinian brothers could liquidate the Palestinian question.”
At the heart of the dispute now is what Cairo sees as a plot by Israel and its backers to force Gaza's 2.3 million residents out of the coastal enclave and into Egypt's sparsely populated Sinai Peninsula.
Egypt sees such a scenario as an unacceptable repeat of the calamitous displacement of hundreds of thousands of Palestinians from their homes at the time of Israel's creation in 1948 and the Middle East war in 1967, known as the “Nakba” or catastrophe.
“Relations are strained in a way that had not been seen in years,” said Michael Hanna, the New York-based director of the US programme at the International Crisis Group. “Egypt is deeply worried about the trajectory of events. It is worried about what comes next as it continues to reject the shifting of the burden of the Palestinian question on to its shoulders.”
That Egypt and Israel made peace in 1979 and forged close security relations in the past decade does not mean differences between them only surfaced after the October 7 attacks.
They have often been at sharp odds over the Palestinian question.
Cairo has repeatedly condemned Israel's heavy-handedness in dealing with the Palestinians.
It has been angered by the construction of Jewish settlements in the occupied West Bank, the killing or arrests of rock-throwing children in Jerusalem and deaths of thousands of civilians in previous Israeli wars against Hamas, among other issues.
But the killing of hundreds of Israelis, including women and children in the October 7 incursion and the subsequent pummeling of the Gaza Strip by Israeli air strikes shed light on how far apart the two nations remain.
President El Sisi's government, for example, has not publicly condemned the killing of hundreds of Israeli civilians in the Hamas incursion. Neither has Cairo publicly offered any condolences. In contrast, the attack was met with an outpouring in the West of sympathy and support for Israel.
And there has been no direct contact between Mr El Sisi and Israeli Prime Minister Benjamin Netanyahu since the Hamas rampage, although it cannot be ruled out that they spoke by telephone but chose not to publicise the call.
In contrast, Mr El Sisi has held talks on the telephone and in person with at least 17 foreign leaders and senior officials since October 7. His Foreign Minister Sameh Shoukry has intensified diplomatic efforts in the same period.
Officially, Egypt's position has essentially been the rejection of targeting civilians on both sides.
Significantly, Egypt has saved its harshest criticism and condemnation for the killing and destruction wrought upon the Palestinians by Israel's air campaign in Gaza, its total blockade of the narrow enclave and its refusal to allow humanitarian aid to alleviate the suffering of residents.
Egypt has also rejected as a breach of international law the demand issued by the Israeli military for more than one million people to evacuate the northern half of the Gaza Strip and move to the south.
“It is better for you to die as knights, heroes and martyrs on your land than to leave it for the usurping colonisers to take,” Sheikh Ahmed El Tayeb, the powerful Grand Iman of Cairo's Al Azhar mosque – the foremost seat of learning for Islam's Sunni majority – told Gaza's Palestinians in a message.
“Let the entire world know that every occupation will end sooner or later and regardless of how long it lasts.”