The landmark reconciliation deal reached last week by the Palestinian factions Fatah and Hamas required compromises on both sides, but none more so than by the Islamist movement that rules the Gaza Strip.

Reflecting on the deal that brought their four-year rift to an end, Khaled Meshaal, the Damascus-based leader of Hamas, said afterward that his side had conceded autonomy on "how to manage the resistance".

The use of violence - along with negotiations with Israel, domestic governance and foreign affairs - will now require Fatah's approval, Mr Meshaal told The Wall Street Journal.

Mr Meshaal did not renounce violence altogether, although it is one of the conditions set by the United States, the European Union, Russia and the United Nations - the so-called Quartet - before it will deal with the Islamist movement.

Nevertheless, Mr Meshaal's grant to Fatah of a veto on armed actions is a recognition that, as he reportedly acknowledged in closed-door meetings, "we cannot do violence and you do non-violence".

He clarified in a later interview that he believed the Palestinians should "have resistance in all forms, armed and public ones" and that he would work to persuade Fatah of this approach. However, Mahmoud Abbas, Fatah's leader, is adamantly opposed to armed struggle.

Just as a change of government in Cairo forced Fatah to reconsider its political position, Hamas's mood of compromise resulted from the shifting fortunes of Syria.

With the sustained protests against Bashar al Assad's regime, the group lost the security of its base in Damascus, said Samir Awad, a politics professor at Bir Zeit University. Rumours now abound that it may move its headquarters to Cairo.

Another factor entering Hamas's political calculations was the plan by the Palestinian Authority president, Mr Abbas, to seek recognition of a Palestinian state at the United Nations in September. That move is opposed by Israel and the United States.

In the past few months, Mr Abbas and Benjamin Netanyahu, the Israeli prime minister, have furiously lobbied wavering foreign capitals, especially in Europe, over recognition. Despite pressure from Israel, the UK and France have indicated that they will back statehood unless Mr Netanyahu makes a serious effort to restart peace talks.

Prof Awad said the need for international backing to attain statehood had "taken the initiative from Hamas" and it was now "resigned to pursuing popular peaceful resistance". In agreeing to unity, he said, Hamas "got behind" Mr Abbas's statehood plan.

However, Hamas has opposed Salam Fayyad, whom Mr Abbas is keen to retain as prime minister in the interim government that will set the stage for the statehood drive and elections. It has reportedly accepted, however, a new draft by Egypt of a deal to secure the release of an Israeli soldier held by Hamas for five years.

A key issue is recognition of Israel. The Quartet has insisted that Hamas not only renounce violence but also recognise Israel. Hillary Clinton, the US secretary of state, said last week that Washington "cannot support" any Palestinian government that included Hamas unless it adopted the Quartet's demands.

At the reconciliation ceremony in Cairo last week, Mr Meshaal said the Palestinian factions had a "common national agenda" of "a Palestinian state in the 1967 lines with Jerusalem as its capital, without any settlements or settlers". Some read into that as tacit recognition of the state of Israel.

Plainly, there are still divisions in the Hamas leadership. Mahmoud Zahar, a senior official in Gaza, said last week that Hamas would never recognise Israel.

Haidar Eid, a professor at al Aqsa University in Gaza, said that Hamas, while ready to make major concessions on armed struggle and a two-state solution, still had red lines, especially over explicitly recognising Israel.

He said he thought last week's unity deal would "survive for a while because Hamas and Fatah have no other options". But he was sceptical that reconciliation could hold in the long term, as it became evident that winning an independent state in the occupied territories was impossible.