Egypt is the crucial, if reluctant, intermediary between Israel and Hamas, which is no great friend of this moderate secular government. Still, a sustained Israeli ground operation in neighboring Gaza would sharply increase public pressure on President Hosni Mubarak of Egypt to do more to help the Palestinians there.

Few criticize Mr. Mubarak himself, and there are widespread feelings here that the radical group Hamas provoked the current crisis. Yet there is unhappiness with the government’s relative silence about Israel’s bombing campaign and its Palestinian victims, and with the apparent lack of diplomatic pressure from Cairo on Israel and the United States to stop the fighting.

Instead, government officials including Mr. Mubarak and Foreign Minister Ahmed Aboul Gheit have blamed Hamas for abandoning the cease-fire with Israel and seeming to seek Israeli retaliation. On Thursday, for example, Mr. Aboul Gheit said that Egypt had warned Hamas of Israel’s intentions, but that Hamas “served Israel the opportunity on a golden platter to hit Gaza.”

Egypt has long been a leader of the Arab world, expected to be the one to stand up to Israel. In the wars of 1948-49, 1967 and 1973, it shed copious blood to try to defeat Israel in the name of Arab nationalism and a Palestinian state. But the former Egyptian president, Anwar el-Sadat, saw it in the country’s national interest for a peace agreement with Israel and was assassinated for that view by Islamic radicals. Those arrested afterward included Ayman al-Zawahri, who later became Osama bin Laden’s deputy.

Mr. Sadat’s successor, Mr. Mubarak, has successfully negotiated the complicated issues of regional security, solidifying a relationship with Washington, maintaining cool but correct ties with Israel and sharply suppressing Islamic fundamentalism and terrorism. But it is a delicate balancing act, said Abdel Moneim Said, director of the Ahram Center for Political and Strategic Studies in Cairo.

Given the continuing Israeli occupation of much of the West Bank and East Jerusalem, deep divisions among Palestinians and a Gaza controlled by Hamas, the Egyptian government “must make difficult choices,” he said.

“Egypt is working for peace while trying to work realistically with the situation in Gaza, where a radical group took over the territories next to Sinai, a sensitive subject for Egypt,” Mr. Said continued. “So Egypt is trying to support Palestinian humanitarian needs, but not allow a radical group to control the situation, dominate the Palestinian issue or affect Egyptian internal politics.”

But such complications are not easy for most Egyptians to grasp, especially when they see the constant repetition of images of Israeli bombs and dead Palestinians on Al Jazeera.

More damaging is a widespread belief that Egypt was complicit in the Israeli attacks, an idea that stemmed from a visit to Cairo by the Israeli foreign minister, Tzipi Livni, the day before the assault began. Traditionally, Israel warns Cairo secretly before taking important military action in Gaza. So the pictures of Mr. Mubarak smiling and shaking hands with Ms. Livni have fueled popular speculation that Egypt was aware of the impending attack and even approved it, to deal a blow to Hamas.

“There is a lot of popular anger over the position of the government, especially that the Israeli foreign minister was here less than 24 hours before the attacks,” said Rania Al Malky, chief editor of Daily News Egypt. “People are putting two and two together and accusing Egypt of complicity. That’s a popular feeling.”

With Israel threatening a ground invasion, the likelihood of more civilian casualties will grow, as will the pressure on Mr. Mubarak to intervene somehow on behalf of the Palestinians. His own position is not at risk, but Egypt already has an important Islamic opposition that could create significant domestic unrest.

The charge of complicity is made loudly by Iranian allies like Hamas and Hezbollah, and slightly less loudly by Syria. They accuse Egypt of bearing part of the responsibility for the Palestinian deaths because of its refusal to open up its border with Gaza. There have been a few attacks on Egyptian diplomatic posts and some, like Hezbollah leader Hassan Nasrallah, have called on Egyptians to rise up and break down the border themselves.

There have been a series of demonstrations, relatively large but controlled by the police, in Cairo organized by the Muslim Brotherhood, an officially outlawed but tolerated fundamentalist party. The demonstrators demanded more action for Gazans. In return for being allowed to demonstrate, observers said, organizers quickly silenced chants criticizing Mr. Mubarak himself.

Cairo residents interviewed on Friday resented the criticism from other Arabs as unfair and unjustified, citing Egyptian aid to Palestinian victims. But they were also uneasy with Cairo’s open blame of Hamas and with its failure to criticize Israel more loudly. Nearly everyone interviewed said they watched Al Jazeera and praised it for its realistic, if bloody, coverage of Gaza, contrasting it with the tame images shown on national television.

“What Egypt is doing is far from enough,” said Gabr Imam Hanef, 57, who runs a parking lot in the poor northwestern district of Cairo around the Sayyida Zeinab mosque. “Hosni Mubarak has to go to Gaza and talk to Hamas and stand up with them in support, and then he has to talk to the Israelis.”

Mr. Hanef says that Mr. Mubarak is a good man who has kept Egypt at peace, “but he is not doing all he can.” There is not enough pressure on Israel and Washington, he said, and he thought that the demonstrations in Cairo should continue.

At the same time, there is a kind of fatigue with the Palestinians and their problems, and with the idea that Egypt should fight wars for other Arabs who are distant from the conflict.

“I’m very angry at the reaction of Arab countries to Egypt, which has been standing with the Palestinians since 1948,” said Sayed Abdel Rafar, 58, smoking a pipe with his friends at a cafe. “No one has done more for them, and now Arab nations mock us and say we aren’t doing enough. It’s those Arab nations who aren’t strong enough to do anything against Israel and want Egypt to do it for them.”

Mr. Rafar, a lawyer, fought in the 1967 war. “I’ve seen war, and we don’t want our children to go through what we did,” he said. “We have a strong military, but if we’re going to war, we’re going to defend our country.”

Another cafe patron, Muhammad Omar, 52, said, “These are people who live with words only. They haven’t been in our place; they haven’t seen what Egypt has seen. And they are often the richest countries, with no trouble eating, while we give the Palestinians food when there are Egyptians who are hungry.”

Hamdan Abdel Hafiz, the cafe waiter, broke in. “We live from pound to pound,” he said, referring to the Egyptian currency, worth 18 cents. “If we get a pound, we eat.”

Those demanding that Egypt open the Gaza border do not understand the dangers, said Samir Abdel Haadi. “If we opened it, we’d be the Iraq of the Palestinians,” he said. “There will be terrorism in the Sinai, and that’s our country.”

Ms. Malky, the editor at Daily News Egypt, said that the government is making it clear it wants Hamas to fail. “They’re afraid of the internal situation,” she said. “They don’t want a successful Islamic or Muslim Brotherhood experiment on their own border.”

But she warned that unpopularity should not be confused with weakness. “The perception of the government in the feelings of the masses is deteriorating,” she said. “But their power and ability to contain whatever dissent may come out has not been shaken in the least.”