With every image of the dead in Gaza inflaming people across the Arab world, Egyptian and Jordanian officials are worried that they see a fundamental tenet of the Middle East peace process slipping away: the so-called two-state solution, an independent Palestinian state coexisting with Israel.

Egypt and Jordan fear that they will be pressed to absorb the Palestinian populations now living beyond their borders. If Israel does not assume responsibility for humanitarian aid in Gaza, for example, pressure could compel Egypt to fill the vacuum; Jordan, in turn, worries that Israel will try to push Palestinians from the West Bank into its territory.

In that case, both states fear, they could become responsible for policing the conflict between the Palestinians and Israel, undermining their peace treaties with Israel.

The Palestinian cause has always been an explosive, emotional and destabilizing one for Arab states. Islamist parties have scored points with the public by making much of traditional Arab leaders’ failure to help the Palestinians. The Gaza conflict, by reigniting these passions, is deepening regional rivalries and further upending traditional balances of power.

Egypt and to some extent Jordan have been thrown off balance by the withering criticism they have faced. Arrayed against them is the alliance of Iran, Syria, Hezbollah and Hamas, the quartet that is fighting against a diplomatic solution to the Israeli-Palestinian conflict — and with that, against the two-state solution.

In Egypt, where leaders have been castigated for refusing to keep open the Rafah crossing to Gaza, officials have argued that they are bound by the agreement on border security that followed Israel’s withdrawal from Gaza. But there is an underlying subtext to their message: that Gaza is not Egypt’s problem.

“Gaza is no longer Egypt’s responsibility, and Egypt is determined not to take it back,” said Abdel Raoud el-Reedy, a former ambassador to the United States who is the chairman of the Egyptian Council for Foreign Affairs.

Egypt controlled Gaza, a 140-square-mile coastal strip, until the 1967 war with Israel. Now, Egypt is trying to negotiate a cease-fire there, because resolving the conflict is very much in its interests. Representatives of Hamas were in Cairo on Sunday and representatives from Israel were expected to arrive Monday, officials said.

Hamas wants the border open, but Egypt has refused, except for humanitarian passage for the injured coming out and medicine going in. Israel wants an international force on the Egyptian side of the border, to prevent smuggling through illegal tunnels, but Egypt has refused, saying that would undermine its sovereignty.

Rather than saying explicitly that Egypt does not want responsibility for Gaza, the authorities have stressed that Israel should be held accountable, while reaffirming their support for a two-state solution.

At a stormy and sometimes defensive news conference in Cairo on Sunday, officials asked why so much attention focused on the one border crossing from Egypt, when there were six crossings from Israel.

“What about the other six crossings?” said Ismail Khairat, the newly appointed head of the State Information Service, without a hint of irony.

Jordanians, too, are anxious. “It is a real concern in Jordan,” said Adnan Abu Odeh, who was an adviser to King Hussein.

While the prospect of having to absorb the West Bank may be remote, Jordan does not want to have to do so, fearing it would destroy the fabric of society in the country, where about half the population is of Palestinian origin.

“This kind of formula means a Palestinian loss of their land and a Jordanian loss of their identity,” Mr. Odeh said.

The fight has accelerated a regionwide battle for influence among Muslim states that was heating up even before the Israeli military attacked Gaza in response to rocket fire from Hamas.

The greatest enmity has developed between Iran and Egypt, though just a few months ago it appeared the two were moving toward normalizing diplomatic relations, which had been downgraded when Iran named a street after Anwar el-Sadat’s assassin.

“The horrible crime of the Zionist regime in Gaza has once again revealed the bloodthirsty face of this regime from disguise,” Iran’s supreme religious leader, Ayatollah Ali Khamenei, said late last month.

Then, singling out Jordan and Egypt, he said, “But worse than this catastrophe is the encouraging silence of some Arab countries which claim to be Muslim.”

At the moment, it appears that Iran and its allies have the upper hand, at least in terms of public relations — a turn that seems to have shocked the Egyptians and rattled the authoritarian state’s sense of control.

Mohamed Bassiouny, a former Egyptian ambassador to Israel who is now a member of Parliament, was nearly shouting Sunday as he tried to champion Egypt’s cause.

“The problem is there is a conflict of wills between two groups,” he said. “One group headed by Egypt, this group is pushing for peace and tranquillity and stability, and there is another group headed by Iran pushing for escalating the situation and stopping all kinds of efforts for tranquillity.”

Egypt has struggled to assert its role as the traditional diplomatic center of the Arab world, with some self-promotional fanfare and little results. It engaged the formal international system of diplomacy to resurrect the peace process.

But its opponents have refused to grant political legitimacy to a process they see as biased against them.

Egypt has been fading as a center of regional influence for years, weighed down by poverty, enormous population growth and political stagnation. Even though the mood on the street has changed, its leaders have held tight to the notion that abiding by the 1978 Camp David accord to normalize relations with Israel and pursuing a two-state solution were in Egypt’s best interests.

The fighting in Gaza exposed the fragility of that approach, and the frantic tone of the Sunday afternoon news conference suggested that the government had not yet figured out how to respond.