A few Israel Defense Forces Engineering Corps officers surely shed a tear yesterday while viewing the television reports from Rafah: The barrier built by the IDF with blood and sweat along the Philadelphi Route, on the Gaza Strip border with Egypt, was coming down.

It was, apparently, the final remnant of Israel's years of occupying the Strip. But Israel has better reasons to be worried by what happened yesterday. In destroying the wall separating the Palestinian and Egyptian sides of Rafah, Hamas chalked up a real coup. Not only did the organization demonstrate once again that it is a disciplined, determined entity, and an opponent that is exponentially more sophisticated than the Palestine Liberation Organization. It also took the sting out of the economic blockade plan devised by Israel's military establishment, an idea whose effectiveness was doubtful from the beginning but whose potential for international damage was not.

Israel, Egypt and the Palestinian Authority are now forced to find a new joint border control arrangement, one that will probably depend on the good graces of Hamas. If the PA is indeed interested in taking responsibility for the border crossings, as Prime Minister Salam Fayyad has declared, it will have to negotiate with Hamas even though President Mahmoud Abbas is trying to avoid that at any cost. The other option - to leave the border untended - is even worse.

The Hamas action yesterday was anything but spontaneous. It was another stage in the campaign that began in Gaza's night of darkness on Sunday. As Gaza was plunged into widely televised blackness, Palestinian children armed with candles were brought out on a protest march and organized into prime-time demonstrations in support of the Egyptian and Jordanian branches of the Muslim Brotherhood.

On Tuesday, Hamas put together a violent demonstration that ended in a confrontation with Egyptian police officers at the border, and, as usual, broadcast live on Al-Jazeera. Apparently it was enough to make Egypt lose its appetite for confrontation.

Yesterday, tens of thousands of people burst through to the west. President Hosni Mubarak explained that he instructed his police officers not to block the hungry on their way to grocery stores in El-Arish and the Egyptian side of Rafah.

Mubarak also had to contend with domestic politics. The violent suppression of the Palestinian masses would have turned up the tension between him and the Muslim Brotherhood, or Al-Jazeera. More than a few Arab commentators now see the Qatar-based satellite channel as the superpower of the Arab world. In many cases its broadcasts clearly promote an Islamic agenda.

Explosions were set at 20 points along the border fence, clear evidence of a campaign that was planned and coordinated well in advance. Israeli intelligence officials will have to explain, to themselves and the country's leaders, whether and how the preparations took place without their knowledge - another Gaza goof, in the wake of the Hamas election victory in January 2006 and the rapid military drubbing it gave Fatah in the Strip last June.

Most of the Gazans who crossed into Egypt are expected to return home within a few days, after stocking up on staples and meeting with relatives they have not seen for years. Meanwhile, Egyptian security forces set up dozens of checkpoints to prevent the Gazans from spreading into other areas of Sinai.