Three years after Israel and Egypt imposed an embargo on this tormented Palestinian strip, shutting down its economy, a consensus has emerged that the attempt to weaken the governing party, Hamas, and drive it from power has failed.

In the days since an Israeli naval takeover of a flotilla trying to break the siege turned deadly, that consensus has taken on added urgency, with world powers, anti-Hamas Palestinians in Gaza and some senior Israeli officials advocating a shift.

In its three years in power, Hamas has taken control of not only security, education and the justice system but also the economy, by regulating and taxing an extensive smuggling tunnel system from Egypt. In the process, the traditional and largely pro-Western business community has been sidelined.

This may be about to change.

“We need to build a legitimate private sector in Gaza as a strong counterweight to extremism,” Tony Blair, who serves as the international community’s liaison to the Palestinians, said in an interview. The views of Mr. Blair, a former prime minister of Britain, reflected those of the Obama administration as well. “To end up with a Gaza that is dependent on tunnels and foreign aid is not a good idea,” he said.

Businesspeople in Gaza say that by closing down legitimate commerce, Israel has helped Hamas tighten its domination. And by allowing in food for shops but not goods needed for industry, Israel is helping keep Gaza a welfare society, the sort of place where extremism can flourish.

“I can’t get cocoa powder, I can’t get malt, I can’t get shortening or syrup or wrapping material or boxes,” said Mohammed Telbani, the head of Al Awda, a cookie and ice cream factory in the central town of Deir al Balah. “I don’t like Hamas, and I don’t like Fatah. All I want is to make food.”

In June 2007, after winning parliamentary elections the previous year and uneasily sharing power with the Fatah-led Palestinian Authority, Hamas took full control in a four-day civil war, leaving the Palestinian Authority restricted to the West Bank.

Israeli officials say they have been working for months on a change of policy, but they want to guard against helping Hamas or bringing renewed rocket attacks on Israel. Israel imposed the embargo in part to prevent Hamas from receiving rockets and other weapons, in particular from Iran.

Israeli officials are less convinced than foreign leaders about the benefits of a full-scale tilt toward the business community, but they see room for increased activity.

“Hamas is strong,” Maj. Gen. Eitan Dangot, the Israeli Defense Ministry official in charge of Palestinian civilian issues, acknowledged. “It controls Gaza, and it doesn’t look like that is going to be changed in the coming months or maybe years. But we must protect our security while helping interests in Gaza that are not under Hamas’s control.”

For Israel, any shift in Gaza is complicated by the fact that Hamas has been holding one of its soldiers for four years. In addition, Israel does not want Hamas or its associates to gain credit for new relief.

This is a problem for Olfat al-Qarawi, stuck in a makeshift tent with her husband and six children 18 months after their house was destroyed by an Israeli invasion. The Qarawis expected to get a donated trailer last year, but it went to a family loyal to Hamas, she said.

When a charity official told her that she would receive one of 200 prefabricated homes arriving on the aid flotilla, she was elated. When the Israeli Navy confiscated the cargo in the raid that killed nine Turks, she fell into despair. The group that had promised her the house was the Islamic Turkish charity known by the initials I.H.H., a sponsor of the flotilla.

Mehmet Kaya, who runs the I.H.H. office in Gaza, says his group sponsors 9,000 orphans, helps with a hospital and runs job-skills training sessions. He said that the flotilla carried not only the 200 prefabricated houses but enough building materials for another 200. He was the one who promised Ms. Qarawi a house.

“We only work through Hamas, although we don’t limit our aid to its followers,” he said. “We consider Israel and the United Nations to be the terrorists, not Hamas.”

The I.H.H. cargo is sitting at the border in Israel, which is trying to find a more appealing partner to distribute it. That may prove difficult. Meanwhile, Turkish flags are fluttering across Gaza, people are giving their babies Turkish names and Ms. Qarawi still lives in a tent.

“I fear we will die here,” she said of the rusting pipes and frayed plastic sheeting that serve as her home in the village of El Atatra, in northwest Gaza. “They won’t have to move us far,” she added with dark mockery. “The cemetery is up the road.”

In truth, most of the postwar tents are gone now, and daily life is neither as awful as many abroad assert nor as untroubled as Israel insists. Instead, it has a numbing listlessness.

“In Gaza, no one is dying,” said Amr Hamad, deputy secretary general of the Palestinian Federation of Industries. “But no one is living.”

For Omar Shaban, who runs a research center called Pal-Think for Strategic Studies, the key to understanding the impact of the siege and Hamas rule is to understand Gaza.

“Don’t compare us with Sudan or Haiti,” he said. “We are an educated people with 2 percent illiteracy. But Israel’s effort to say that everything is O.K. here is ridiculous. I can’t travel. Students are trapped.”

Israel imposed the embargo, allowing in charitable goods and letting out people with medical emergencies. It invaded in late 2008 to stop a flow of rockets and destroyed thousands of buildings. With almost no construction materials allowed in, Gazans have scrounged from the rubble to create their own, but there has been only limited rebuilding.

Egypt, which dislikes Hamas for its Islamist ideology and Iranian backing, imposed the same closing from the south.

The idea was that the West Bank would prosper while Gaza would fester. That has happened, but it has done less than expected to change the power dynamic and has caused much suffering.

Mahmoud Daher of the World Health Organization said that both chronic and acute malnutrition had crept up, and that hospitals waited up to a year for vital equipment like CT scanners, X-ray parts and infusion pumps. Mr. Hamad estimated that political loyalties in Gaza were divided into equal thirds: pro-Hamas, pro-Palestinian Authority and independent, many in the private sector. He has been telling foreign officials that if they helped foster businesses, there could eventually be a majority coalition of non-Hamas parties here.

Under current circumstances, he said, the soil for extremism remained fertile.