The answer, delivered by the Lebanese information minister, Tarek Mitri, was that Lebanon would follow “Arab consensus” in deciding whether to attend.

No one laughed, but the comment could have passed for black humor. Arab leaders remain cripplingly divided on how to respond to the crisis, which has left more than 1,100 dead in Gaza. Despite a rush of diplomatic meetings – two simultaneous ones on Friday in Qatar and Kuwait, and two more expected next week – there was still no agreement on convening the Arab League, the body that is meant to bring Arabs together on issues of mutual concern.

In the end, the Lebanese president, Michel Suleiman – having struggled to find a balance between the conflicting demands of his country’s own factions – attended the meeting in Doha, Qatar, on Friday. But leaders of three of the most important Arab countries – Egypt, Jordan and Saudi Arabia – refused to attend, and so the meeting did not qualify as a league summit and only underscored the region’s divisions.

“The boat is sinking,” said Amr Moussa of Egypt, the Arab League’s secretary general, in unusually dire comments during a news conference in Kuwait, where foreign ministers met Friday afternoon. “I’m very frustrated regarding the stance of Arab countries.”

The inability of Arab governments to take any collective or decisive action on Gaza is rooted in two basic trends, said Rami Khoury, the director of the Issam Fares public policy institute in Beirut. Most Arab regimes are terrified of Islamist movements like Hamas, which represent the greatest threat to their legitimacy. Many, including Egypt and Jordan, face challenges at home from their own popular versions of the Muslim Brotherhood, Hamas’s ideological parent. Most Arab leaders are also reluctant to provoke the United States and Israel (with which Egypt and Jordan have peace treaties).

For those reasons, Egypt and Saudi Arabia have refused to endorse a meeting of the Arab League. They do not want to be embarrassed by figures like Syria’s president, Bashar al-Assad, who – like his Iranian allies – has won points with an angry Arab public by supporting Hamas and inveighing against the passivity of other Arab leaders.

On Friday, Mr. Assad took his attacks a step further at the Doha gathering, deriding the Saudi-sponsored proposal for a peace plan with Israel as “already dead,” and calling for all Israeli embassies in Arab countries to be closed. Soon after he made his comments, Qatar and Mauritania announced they were cutting their economic and diplomatic ties with Israel, in another sign that countries like Egypt, Jordan and Saudi Arabia, who support a diplomatic approach with Israel, could become isolated if the violence does not end soon.

Mr. Assad’s broadside was also a reminder that the perennial fractiousness of Arab politics goes deeper than disagreements on politics and religion. Syria’s differences with Saudi Arabia, which stem from Syria’s ties with Iran and its suspected role in an assassination in Lebanon in 2005, have been exacerbated by a personal feud between the Saudi king and Mr. Assad that began with Mr. Assad publicly insulting the king two years ago and is likely to be worsened by the bitter accusations of the past few weeks. Even where two countries share the same ideology and politics, personal differences between leaders have sometimes maintained a rift. Syria and Iraq were ruled for decades by the Baathist leaders Hafez al-Assad (Bashar’s father) and Saddam Hussein, whose rivalry kept their countries bitterly divided.

“One of the problems with Arab politics is that it remains tribal and personal and that is why Arabs cannot agree about anything,” said Hilal Khashan, a professor of political science at the American University in Beirut.

Yet today’s inter-Arab tensions are not just about Gaza, or relations with the West, or even personal disputes. Many Arab leaders believe that Iran is aiming to become the dominant power in Middle East, and is using the Palestinian issue to batter its rivals through Hamas, its client.

“What’s happening in Gaza is dangerous on its own, but also dangerous in its implications,” said a Jordanian official who spoke on condition of anonymity because he was not authorized to discuss the issue. “Iran is interested in prolonging the violence, because that would help it to mobilize the Arab street and turn people here against their governments.”

That broad political threat to moderate Western-leaning governments may outweigh the sectarian anxieties provoked by Iran’s Shiite theology as its national power rises. Iran, after all, has now helped empower a Sunni Islamist movement, Hamas, as well as a Shiite Islamist movement, Hezbollah, and together the movements can claim a popular following across theArab world.

To many on both sides of the Arab divide, the battle in Gaza is a kind of replay of the 2006 war between Israel and Hezbollah. Then, as now, Israel mounted vastly more destructive attacks in response to the Islamists’ launching of rockets into populated Israeli areas. In a sense, the strategy worked: the Israel-Lebanon border has been quiet ever since. Even after the Gaza war began, Hezbollah restrained its militia from any attacks, knowing it could lose much of its political support within Lebanon if it were to draw the country into another devastating war. Now Israel, in Gaza, clearly hopes to limit Hamas’s future military options as well, mainly through agreements that could choke off its weapons supply network.

Yet the 2006 war strengthened Hezbollah politically, and the group now seems likely to win a majority in the parliamentary elections later this year, a pivotal development. Many people in Lebanon fear that the current war could bring similar new strength to Hamas, even as it inflicts political damage on its foes in the Arab world.

“It may take some time, but Hamas will take over the West Bank,” said Sarkis Naoum, a political columnist for the Beirut newspaper Al Nahar.

That, Mr. Naoum added, would put Hamas’s patrons, Syria and Iran, in a much stronger position vis-à-vis the other Arab countries. It may also – not coincidentally – put Syria and Iran in a stronger position vis-à-vis the United States, should Barack Obama follow through on his proposal to talk directly with them.

Some Western-leaning Arabs fear that Lebanon, with its welter of competing factions, could be an indicator of where the broader Arab world is heading. The president, Mr. Suleiman, has struggled to steer a neutral course between the country’s two major political camps, one allied with the West, the other with Iran. But his efforts to find an “Arab consensus” have become more and more difficult.

On Thursday, Hezbollah arranged street demonstrations, as if to remind Mr. Suleiman who wears the pants in Lebanon. Mr. Suleiman got the message. He got on a plane and went to Doha, alongside the Syrian president and the leader of the Hamas military wing.