The accord struck between Fatah and Hamas that could end a bitter four-year feud will please a Palestinian public longing for a united leadership.

Thousands in the Hamas-controlled Gaza Strip and the Fatah-dominated West Bank rallied last month to demand that their leaders act, "with one hand". Their protests appear to have succeeded.

The factions, after mediation by Egypt's transitional government, agreed on Wednesday to form an interim authority until elections are held within a year. Then, many hope, the Palestinians will once again fall under one government.

"Most would be happy because of this, because it's better than being divided," said an optimistic yet cautious Maria Hraish, a pharmacist who lives in Ramallah.

But aside from announcing an auspicious start towards reconciliation, officials from both Hamas and Fatah have presented scant details on how they intend to move ahead while disagreeing on so many fundamental issues.

Uzi Rabi, a professor of Middle East studies at Tel Aviv University, said this was evidence that the agreement was more a "tactical move" by both sides than anything else. Eventually, he said, "the differences between Fatah and Hamas wwill be exposed".

Chief among them is the still-unresolved question of what to do with their respective security networks, each of which is pulled in opposite directions by support from the United States and Iran.

Moreover, Hamas and Fatah have used their powerful security agencies for arresting and intimidating each other's members, exacerbating the bad blood between the two.

Even so, analysts say, the combination of domestic pressure favouring reconciliation and the impact of regional uprisings compelled the two factions to try to mend their differences.

Emad Gad, a Cairo-based expert on Israeli-Egyptian relations, said Hamas was also motivated by the fear that one of its main supporters, the Syrian government, could collapse.

"Hamas's situation in Damascus is precarious, so the Islamist group is looking to keep the door open with Egypt in case the Syrian sponsorship fails them," he said.

Even if they loathe Gaza's Islamist rulers, Fatah officials, including its chairman and Palestinian Authority (PA) president, Mahmoud Abbas, probably find the agreement useful in gaining international support for an independent state.

They intend to present their case for independence at the United Nations in September.

"If there's a united Palestine, that makes a big difference in whether to vote in support of a Palestinian state," said Itzhak Galnoor, a professor of political science at Hebrew University and fellow at the Van Leer Jerusalem Institute.

He added that it also makes it difficult for Israel's prime minister, Benjamin Netanyahu, to argue against holding peace talks because the Palestinians are divided. And arguing against reconciliation because it involves Hamas, as Mr Netanyahu also has done, would be a "difficult position to advance, unless you are willing to forget what you said before," Mr Galnoor said.

Palestinians involved in the reconciliation effort acknowledge that the agreement's timing was, in part, an attempt to pre-empt a speech next month by the Israeli leader in front of the US Congress.

During the address, Mr Netanyahu is expected to lay out his own peace plan as an alternative to direct peace talks that faltered last September, in large part because of his refusal to extend a freeze on settlement construction. The Israeli leader has since come under increasing criticism domestically and internationally for his role in the peace process.

But his alternative peace proposal is expected to fall far short of Palestinian demands.

"That's one factor" behind the agreement's timing, "because Netanyahu is bent on destroying the possibility of a Palestinian state, and because of his stubbornness at the negotiating table," said Mustafa Barghouti, a prominent Palestinian politician who took part in the reconciliation efforts.

Yet the two seem headed towards seemingly insurmountable differences, such as how to handle the United States, which prefers Palestinians talks with Israel rather than pressure it by earning diplomatic support for an independent state.

This already seems a point of contention between Hamas and Fatah, which runs a Palestinian Authority heavily reliant on US financial support.

While Mr Abbas has signalled that peace talks could be continued under an interim Palestinian government, Mahmoud Zahar, an influential Hamas hardliner, flatly rejected the idea on Wednesday.

For Palestinians such as Shadi Ali, 37, an accountant who works in Ramallah, this sort of snub to a global superpower and its interests could be risky. The US is Israel's staunch ally, it considers Hamas a terrorist group, and, according to Mr Ali, it alone can decide whether the Palestinians will ever have their own state.

"If America really wanted to make a solution for the Palestinians people, they could do it tomorrow," he said as he walked along Ramallah's Manara roundabout, the site of March's unity protests.