Fifty years after the Yom Kippur War, which began after a surprise attack by Egypt and Syria on Israel, Palestinian militants launched a major attack during the Jewish holiday, sparking a strong response from Israel.

Tensions had recently risen in the Gaza Strip, but the conventional view was that neither Hamas, the Islamist group that rules there, nor Israel wanted an escalation, the BBC and correspondent Yolande Knell report in an analysis. Instead, Hamas was planning a sophisticated, coordinated operation. Early yesterday morning, as an intense barrage of rockets was fired, some reaching as far as Jerusalem and Tel Aviv, Palestinian fighters entered southern Israel by sea, land and air.

They held Israeli towns and military outposts under siege for hours, killed many people, and took an unknown number of Israeli civilians and soldiers to keep as hostages in Gaza.

Thousands of Israelis who had gone out for a nightly revelry in fields near Gaza quickly came under fire. Footage showed bystanders running for their lives.

After her partner drove to find her, Gili Yoskovich told the BBC how she hid from the heavily armed fighters among trees. “They were going from tree to tree and shooting everywhere. From two sides and I saw people dying everywhere.” “I said, ‘OK, I’m going to die, it’s okay, just breathe, just close your eyes,’ because [εκεί] they were shooting everywhere. He was very, very close to me.”

The Israel HaYom newspaper quoted Ella, a resident of Kibbutz Be’eri, as speaking of her fears for her father, who had gone to a safe room after sirens went off to warn of incoming rocket fire.

“He wrote to me that the terrorists are in the shelter, I see his picture on Telegram from inside Gaza. I still hear bursts of gunfire,” he said.

Many Israelis expressed shock that Israeli security forces did not come to their aid sooner. Meanwhile, footage shared on Hamas channels showed that soldiers at Israeli military positions and a tank had been captured or killed.

There were initial images of celebrations in Gaza where hijacked Israeli military vehicles were driven through the streets.

“I am happy with what Hamas has done so far, taking revenge for the Israeli actions at al-Aqsa,” a young man in Gaza City told the BBC, referring to the recent increase in Jewish visitors to the compound in the Israeli-annexed East Jerusalem during the High Holidays.

The al-Aqsa Mosque is the third holiest site in Islam and is also the holiest site for Jews, known as the Temple Mount. Still, the man, who was fleeing his apartment after warnings that the Israeli army was about to strike nearby, expressed fear of what would happen next.

“We are worried, already my family lost our shop when the Shorouk tower was hit by Israel in the 2021 war,” he said. “The action taken by Hamas this time is much bigger, so there will be an even bigger Israeli response.”

Palestinian hospitals have already been overwhelmed by casualties from Israeli airstrikes that have caused extensive damage.

The Gaza Strip – a tiny coastal enclave home to around 2.3 million Palestinians – was seized by Hamas in 2007, a year after it won parliamentary elections. Israel and Egypt then tightened the blockade of the area. It remains impoverished with around 50% unemployment.

After the serious conflict between Israel and Hamas in 2021, indirect talks brokered by Egypt, Qatar and the UN helped secure thousands of permits for Gazans to work in Israel and ease other restrictions in exchange for relative calm .

Last month, when hundreds of Palestinians began demonstrating alongside the perimeter fence in the strip, in a reminder of the mass protests that began five years ago, it was seen as a nod to Hamas and aimed at extracting more concessions from Israel and aid money from Qatar.

Small rallies now look like a red flag. Some have speculated whether it was actually an opportunity to inspect the fence before the infiltration. With this latest operation, Hamas appears to wish to once again upgrade its credentials as a militant organization. Its charter remains committed to the destruction of Israel.

Speaking at the launch of the offensive, Hamas’s shadow militant commander, Mohammed Daif, called on Palestinians and other Arabs to join the action to “sweep the [ισραηλινή] occupation”.

A big question now is whether Palestinians in the occupied West Bank and East Jerusalem or elsewhere in the region will heed his call. Israel undoubtedly sees the possibility of a war that could break out on multiple fronts.

The worst-case scenario is that he could enlist the powerful Lebanese militant group Hezbollah. Meanwhile, the Israeli military has ordered a massive reinforcement of troops. In addition to heavy airstrikes in Gaza, it has said it is planning a ground operation there.

The capture of Israeli soldiers and civilians, whom Palestinian fighters will hope to use as human shields or bargaining chips, is a serious complication.

“Right now we are busy regaining control of the area, striking broadly and taking special care of the area around the Gaza Strip,” said IDF spokesman Rear Admiral Daniel Hagari. “We’re going to do a very vigorous and thorough review.”

While a full review may still be long overdue, there is no doubt that Israel’s intelligence and security establishment will be wondering how it did not see this action coming and how it failed to prevent its massive consequences.