If Palestinian Authority President Mahmoud Abbas of the mainstream Fatah party makes good on his threat to resign, the man constitutionally assured his post is from the rival Hamas faction.

His name is Aziz Dweik, a leading member of Hamas who was released from Israeli prison this summer after being held for three years.

Among 41 elected Hamas lawmakers – nearly a third of the Palestinian parliament – rounded up by Israel following the 2006 kidnapping of Israeli soldier Gilad Shalit, Dr. Dweik was one of the most prominent. His resume boasts spectacular English, a PhD in urban planning from the University of Pennsylvania, and a key spokesman on behalf of 415 Hamas members deported to Lebanon in 1992. (With the help of international pressure, they were quickly returned.)

Saeb Erekat, the chief Palestinian negotiator under Abbas, has said repeatedly in recent weeks that if his boss goes, Dweik is next in line. Some Palestinians go even further, pointing out that Abbas's term actually expired in January 2009, and that legally, Dweik should replace him.

"Abu Mazen's term ended long ago," says Dweik in a conversation in his home in the West Bank city of Hebron, referring to the embattled Palestinian president by his patronym. "If it were challenged in a constitutional court, I'm pretty sure he would lose."

Dweik says he's not agitating for the top seat, however. He is focused instead on trying to bring about a reconciliation between Fatah and Hamas, without which the Palestinians cannot claim to have their own house in order and are thus weakened in peace talks with Israel.

As a member of Hamas, but one who does not view violence as the answer, Dweik sees himself as a bridge between the Islamist organization and the secular Fatah party.

Two issues holding up Fatah-Hamas deal

The Egyptian-brokered reconciliation deal that over the past six months has repeatedly been reported as just around the corner is in fact close, Dweik says, but two major issues are holding it up.

One, Hamas wants about 1,000 Hamas-affiliated Palestinians fired from various government jobs and teaching positions to be reinstated. Second, it seeks the release of some 900 Hamas prisoners the Palestinian Authority swept up in its West Bank law-and-order crackdown, carried out with the help of the US security coordinator in the West Bank, Lt. Gen. Keith Dayton.

"We have to insist on that [their release], or we will sell out our own people," Dweik says. "Of the 900, 99 percent of them are not fighters. But some of them used to serve us in election time as part of our canvassing teams." In short, the reason Hamas will not agree to a deal that doesn't include them is because to do so would mean that its grassroots activists will remained jailed and incapacitated – a key problem given that the reconciliation deal is expected to pave the way for elections.

Lastly, he says, while Hamas agrees in principle to letting a force of 3,000 Presidential Guards – loyal to Abbas – enter Gaza, Fatah negotiators won't reciprocate by allowing anyone from Hamas's security apparatus to come into the West Bank.

If Fatah did meet some of these demands, it would surely not be looked on favorably by Israel or the international community, which has demanded that Hamas recognize Israel and accept previous peace agreements with it in order to be counted as a legitimate political player.

'With absolutes, we'll get nothing'

Though a deeply religious man ("Abu Mazen is not afraid of the hereafter, but I am," he offers), Dweik does not subscribe to the fiery rhetoric the West has come to expect of militant Islamists.

"There's a proverb in Arabic: If you can crack the nut with your fingers, you don't have to crack it with your mouth," says Dweik, who wears a trim white beard and is the father of seven grown children, most of them with their own advanced degrees. "If we can solve this conflict by peaceful means, why solve it by violent means?"

The recurring flaw, he says, is that too many people – his compatriots and his adversaries – refuse to accept not having it all.

"In 1948, the Arabs demanded absolutes, saying we have to destroy Israel and liberate all of Palestine. Israel is now demanding absolutes by wanting to keep building settlements," he says. "But whoever demands these absolutes will get nothing. In the past, we demanded it all, and we got absolutely nothing."

If Hamas were to join a new Palestinian unity government that then reached a peace treaty with Israel, Dweik says the Palestinian Authority should put it to the people in a referendum. But Hamas hard-liners say such a treaty – or any such pacts with any "infidels" – is forbidden in Islam, making a truce the most that is likely to be offered.

Experts disagree on Dweik's role

Mohammed Asad Awaiwi, a political science professor at Al-Quds University in East Jerusalem, says that Dweik is known to be balanced, well-liked, and even a critic of some of Hamas's irresponsible moves – and would stand a good chance of winning a government post in future elections.

"When Abu Mazen says he will not run again in any elections because of the failure of the negotiations, and might resign before the elections, it is the right of Aziz Dweik as PLC speaker to replace him until the elections are held," says Dr. Awaiwi. "Why should Fatah enjoy the law when it serves them and manipulate the law when it serves their opponents?"

Bassem Zubeidi, a political scientist at Birzeit University sees it slightly differently.

"Constitutionally speaking, it's true, he should succeed Abbas," Zubeidi says. "But in actual terms, he's not really a player at this point. Not because he's a bad guy, but people here do not see Hamas as a viable option to really govern the Palestinians. I think this issue of Dweik taking over is not serious. It's part of the game: who's more legitimate" – Abbas or Dweik, or more broadly, Fatah or Hamas.

Moreover, the fundamental differences between Fatah and Hamas to remain, he says, with neither wanting to give too much.

"I think they're still not serious enough to close that deal," says Zubeidi. "They're not behaving like they're in a hurry. Part of the gain is that Hamas wants to be acknowledged as a legitimate player, and Abbas is under all kind of pressure not to go for that. He's under pressure from the Israelis and the US, and even other Arab countries are not happy to see Hamas becoming that strong."