The balance of power within Hamas, which Israel, the United States and much of the West defines as a terrorist organization, has been shifting to Gaza, according to experts. The group seized control of the Palestinian coastal enclave in 2007 after beating its main rival, Fatah, led by President Mahmoud Abbas of the Palestinian Authority, in parliamentary elections a year earlier.
In the decade since, Hamas has fired thousands of rockets at civilian centers in Israel, survived three wars against the Israeli Army and, according to Israeli officials, continuously built up its military force.
The group first gained prominence for its terrorist acts, mostly deadly suicide bombings in buses and cafes in Israeli cities during the second Palestinian uprising in the early 2000s.
Juggling militancy with a desire for international recognition, Hamas last week unveiled a new document of principles that is said would guide the group. The paper, meant in part to improve ties with Egypt, waters down the anti-Semitic language of the group’s charter, and accepts at least a provisional Palestinian state, though it still rejects any recognition of Israel. Analysts said that in trying to create a compromise among opposing factions, the new document failed to fully satisfy any of them.
Mr. Haniya, as the leader of Hamas in Gaza since 2006, was associated with the political wing of the movement that, at least nominally, is more involved with diplomacy and governance and less directly with armed struggle.
In February, Yehya Sinwar was elected to succeed Mr. Haniya in Gaza. Mr. Sinwar is known as a hard-liner more closely associated with the group’s militancy.
“The composition of the political bureau in Gaza tends to radicalism,” said Hussam al-Dajani, a Palestinian writer and political analyst in Gaza. “Mr. Haniya is the balance here. He is a flexible person who supports peace and unity and stability in the region.”
Ibrahim Madhoun, a Gaza-based analyst who writes for a Hamas newspaper, said he expected Mr. Haniya in his new role to improve Hamas’s relationships with Egypt, Iran, Qatar and Saudi Arabia. He added, “The elections enhance the democracy and vitality of the movement and give a greater role to institutions, not to people.”
Mr. Haniya, a father of 13, began his rise to prominence in Hamas as a close associate of the group’s founder and spiritual leader, Sheik Ahmed Yassin, who was assassinated by an Israeli airstrike in 2004. Mr. Haniya served several sentences in Israeli jails in the 1980s and ’90s, and briefly served as prime minister of a Palestinian unity government after the 2006 elections.
That government was short-lived, in part because Hamas refused, then as now, to fulfill international conditions for recognition, including renouncing violence, recognizing Israel’s right to exist and accepting signed agreements between Israel and the Fatah-dominated Palestine Liberation Organization.
Last year Avigdor Lieberman, a hard-line Israeli politician, issued a blunt ultimatum to Mr. Haniya. Mr. Lieberman said that if he were defense minister, Mr. Haniya would be dead within 48 hours if he did not return two Israeli men and the remains of two soldiers that Hamas is believed to be holding in Gaza. Mr. Lieberman became defense minister a month later. The threat has so far remained unfulfilled.
