The Egyptian decision to permanently reopen the Rafah border crossing does not end the blockade of the Gaza Strip, but is nevertheless a highly significant development.

According to the new regulations, Rafah will operate for 12 hours, six days a week as a passenger terminal only. Men aged 18 to 40 will require permits to use the crossing and trade - the passage of goods and materials in commercial quantities - continues to be prohibited.

As limited as this relaxation may be, it will make a palpable difference to the population of the Gaza Strip, which for almost half a decade has been isolated from the outside world by the combined efforts of Israel and Egypt.

The blockade was never about preventing the flow of weapons or militants to the Gaza Strip. Following the American-sponsored 2005 Agreement on Movement and Access (AMA), Israel continued to exercise control over the border through EU surrogates - and Israel did not claim a single instance of illicit passage while the Europeans were permitted to perform their role. As Israel knew full well, Hamas and other Palestinian organisations met their needs through a combination of underground and naval smuggling routes augmented by local production.

Rather, as the Israeli rights organisation Gisha concluded on the basis of declassified Israeli documents, the blockade's purpose was to "paralyse normal life" in the Gaza Strip through "a policy of deliberate reduction for basic goods" such as fuel and flour - and outright prohibition on "luxury" goods such as pasta and paper. As expressed by Ariel Sharon's sadistic bureau chief Dov Weisglass in 2006: "The idea is to put the Palestinians on a diet, but not to make them die of hunger."

The motive behind taking the entire civilian population of the Gaza Strip hostage was to overturn the result of the 2006 Palestinian legislative elections won by Hamas and dislodge it from power. As an objective shared by the Palestinian Authority of Mahmoud Abbas and Egypt under Hosni Mubarak, it explained the latter's enthusiastic participation in the scheme.

Indeed, the brutalisation of the Gaza Strip became something of an international cause célèbre; in the aftermath of Israel's 2008-2009 assault on the Gaza Strip, the US Army Corps of Engineers and France helped Egypt construct a high-tech, "impenetrable" underground steel barrier to isolate it further - which was rather effortlessly punched full of holes by Gaza's resourceful tunnellers. Not to be outdone, Israeli naval commandos murdered nine foreign solidarity activists - six of them "summarily executed" in international waters, according to the UNHCR - to prevent the delivery of aid to the beleaguered territory. Incidentally, the UN secretary general Ban Ki-moon on Friday called on governments to use their powers to oppose further aid flotillas.

Yet the equation is clearly changing. With Mr Mubarak's overthrow, Egypt's policy towards the Palestinians is no longer the extension of Israeli and American priorities that it has been for three decades, reduced from a national cause to a security file. As the recent reconciliation agreement between Fatah and Hamas demonstrates, Cairo is once again marching to the beat of an indigenous drummer, its policies increasingly dictated by Egyptian rather than Israeli-American interests.

Tellingly in this respect, Egypt did not invite the EU to resume control of the border crossing, instead treating this as a purely inter-Arab matter in which Europeans serving Israeli interests have no business interfering.

Yet the ascendancy of Egyptian priorities also explains why Cairo is unlikely to go very much further in lifting the blockade of Gaza than it already has. The viciousness of Mr Mubarak and his security chief Omar Suleiman's methods obscured what remains an Egyptian strategic priority: a refusal to once again assume responsibility for the Gaza Strip, and opposition to further fragmentation of the Occupied Territories and the nascent Palestinian polity.

By Egyptian calculations, the free flow of trade across Rafah while Gaza's crossings with Israel remain subject to Mr Weisglass's dietary restrictions would be tantamount to allowing Israel to export the entire territory - and the catastrophic crises it has engineered there since 1967 - to Cairo. It would furthermore serve Israel's objective of enhanced Palestinian fragmentation in order to prevent the emergence of a Palestinian state.

Egypt will therefore continue to insist that Rafah should not function as more than a secondary Gazan window on the world. In response, Israel may decide to turn the screws on the Strip, in the hope that growing domestic pressure on Egypt's new rulers will produce a further relaxation of border controls.

Cairo's new attitude towards the Palestinians is now largely shared by the Fatah movement, which views Palestinian integration - including the free flow of persons and goods between the West Bank and Gaza Strip through Israel - as an essential component of meaningful statehood. Hamas, by contrast, has a more ambivalent attitude. Convinced Israel has no intention of relinquishing its occupation of the West Bank and recognising that the Gaza Strip is ultimately dependent on either Israel or Egypt for access to the outside world, it calculates that Egypt is the more reliable outlet that furthermore offers opportunities for strategic depth.

In the meantime, Gaza remains deprived of a normal trade regime, still suffering an attenuated blockade. Next month's Freedom Flotilla - unimpressed by Mr Ban's insistence on "legitimate crossings and established channels" - aims to confront this continuing reality.