The prisoner exchange between Hamas and Israel that is expected to begin next week could reshape regional relationships, strengthening Egypt, Hamas and Prime Minister Benjamin Netanyahu of Israel while posing an acute challenge to the Palestinian Authority in the West Bank.

One result might be a more confrontational — and Hamas-imbued — Palestinian movement that could, in the long run, increase Israel’s difficulties, drawing inspiration from and invigorating popular protests across the Middle East. It could also tighten the relationship between Hamas, Egypt and Turkey.

“Hamas has been in the shadows, and this moves it into the Palestinian forefront for now,” said Zakaria al-Qaq, a political scientist at Al Quds University in East Jerusalem.

Under the deal, announced on Tuesday, Israel will free more than 1,000 Palestinian prisoners in exchange for the release of Staff Sgt. Gilad Shalit, an Israeli soldier seized in a cross-border raid by Hamas in 2006 and held ever since in Gaza.

President Shimon Peres of Israel announced that Turkey, which has angrily downgraded its relations with Israel in the last year, had played an unexpected role in helping broker the deal. Turkey is close to Hamas.

Some of the details of the Hamas-Israel deal have not been disclosed, making it hard to determine why the two sides suddenly came to agreement after failing to in past years, on what seem to have been similar terms. But the growing turmoil in the region played an important role, as did domestic politics.

Hamas is worried about its base in the Syrian capital, Damascus, given the uprising against President Bashar al-Assad. It is exploring both Turkey and Egypt as possible future bases, and this deal will help it in both pursuits.

Israel, for its part, fears that after elections in Egypt, the government there might not be helpful, so it thought it best to act now.

In addition, Hamas, and to a lesser extent Israel, seemed to be reacting to efforts by the Fatah-dominated Palestinian Authority to gain membership in the United Nations. President Mahmoud Abbas of the Palestinian Authority earned the admiration of many of his people by pressing his case for statehood upon the Security Council, rejecting American requests to withhold the application and refusing to return to negotiations with Israel without a freeze on settlements in the West Bank.

Hamas, which rules in Gaza and calls for Israel’s destruction, has criticized the move, saying it lacked dignity and offered legitimacy to Israel. At the moment, Mr. Abbas is having trouble gathering enough support on the Security Council and among major European powers. Meanwhile, Hamas is promising desperate families of prisoners that they will soon be reunited with their loved ones, some of whom have been in jail for two decades.

For Mr. Netanyahu, bringing home Sergeant Shalit, whose image is everywhere in Israel, offers a significant political boost. The popular yearning for his return is in many ways comparable to the social protest movement here last summer that began with anger over the high costs of consumer goods and income inequality. It cuts across ideological lines and focuses on the perceived failure of the government to honor its social contract with the people: to do all it can to bring back its soldiers and serve its citizens.

Returning Sergeant Shalit to his family is likely to soften Mr. Netanyahu’s image as someone too focused on geopolitics and insufficiently caring toward average people and their daily concerns. It may also force the social protest movement to reduce its criticism of him, at least temporarily, building unity in an often fractured society and extending his government’s time in office.

For Hamas, the timing of the swap agreement is almost ideal. Anger over the conditions of Palestinian prisoners in Israel has been growing in the West Bank, and Wednesday was a strike day in support of the prisoners, with government offices and universities closed.

In the West Bank city of Hebron, in front of thousands of people gathered in the main square in support of the prisoners, the local Fatah leader, Kifah al-Owiwi, congratulated Hamas — a rarity — and asked it to work harder at reconciling the two movements.

Hamas made a point in its negotiations with Israel of insisting that all Palestinian factions, as well as Israeli Arabs and Jerusalem residents, be represented in the prisoner release, giving it the ability to say that it is taking care of all Palestinians.

“Hamas is now gaining clout domestically and regionally, and this will strengthen the demands for reconciliation with Fatah to proceed,” said Khalil Shikaki, a political scientist in Ramallah. “And if the Muslim Brotherhood gains in elections in Egypt, as many expect, that improves Hamas’s position even more.”

Israel and Hamas are sworn enemies, but Israeli officials are also angry at Mr. Abbas for his United Nations move.

“Preserving Abbas’s image is no longer so important for Israel, which was happy to give him a slap in the face,” said Yitzhak Reiter, a professor of Islamic and Middle Eastern Studies at Hebrew University in Jerusalem.

At the same time, Israel worries about having to contend with dozens of convicted militants’ suddenly being freed, some of them to the West Bank. At an intelligence briefing for Israeli journalists, it was disclosed that the perpetrators of some of the most notorious and murderous attacks would be freed, although not all to the West Bank.

Yaakov Amidror, Israel’s national security adviser, said on the radio that because the Israeli military maintained tight control of the West Bank, he was not so worried about the men who would be released there.

It appears that both sides did yield on some long-held positions in the negotiations. Hamas agreed to remove from its list of prisoners some of the most notorious from Israel’s point of view. Marwan Barghouti, of Fatah, who is seen as a likely future leader, was also removed at Israel’s insistence. Hamas accepted that some prisoners would be sent into exile for a period of years, which it had previously rejected.

“The greatest disagreement inside Hamas was if we should agree to the expulsion of such a large number of prisoners,” said Ribhi Rantisi, a Hamas activist in Gaza, on Israel Radio. “But they agreed and this was really the biggest concession.”

Fawzi Barhoum, Hamas’s spokesman in Gaza, said that at the outset of “five years of difficult negotiations” Israel had demanded the release of Shalit with “no price,” offering only to ease the blockade on Gaza. But, he said, Israel relented partly because the Arab Spring was changing the situation in neighboring countries.

He also appeared to suggest that some prisoners could be released to Arab countries, saying that “any deportation of any prominent member or detained people from occupation jails to any Arab countries during the spring of the Arab revolution” might prove to be only temporary in the new political climate in the region, and would be “a step to return back again to Palestine.”

For its part, Israel agreed to allow more prisoners back into the West Bank even though the history of such releases suggests that some released killers return to violence. One reason it did so was its belief that the Palestinian security forces there are more dedicated to stopping violence and more effective at it as well. But this exchange could also weaken the Palestinian Authority in the West Bank.

If talks over a future Palestinian state fail to resume, if the United States Congress cuts off aid to the Palestinian Authority because of its United Nations bid and if fears heighten of growing Hamas influence, those security forces may shift their focus.

In addition, if Syria implodes and Egypt fails to achieve democratic reforms while Israel’s hawkish right wing grows stronger, the Shalit exchange may end up damaging Israel’s interests more in the long run than it helps them in the immediate future.