Something odd is going on in Egypt these days. About 1400 activists from all over the world gathered there on their way to the Gaza Strip.

On the anniversary of the so-called Operation Cast Lead, they intended to participate in a non-violent demonstration against the ongoing blockade, which makes the life of 1.5 million inhabitants of the Strip intolerable. At the same time, protests were to take place in many countries. When the international activists arrived in Egypt, a surprise awaited them. The Egyptian government forbade their trip to Gaza. Their buses were held up on the outskirts of Cairo and turned back. Individual protesters who succeeded in reaching the Sinai in regular buses were taken off. The Egyptian security forces conducted a regular hunt for the activists. The angry activists besieged their embassies in Cairo. On the street in front of the French embassy, a tent sprang up which was soon surrounded by the Egyptian police. American protesters gathered in front of their embassy and demanded to see the ambassador. Several protesters who are over 70 years old started a hunger strike. Everywhere, the protesters were held up by Egyptian elite units in full riot gear, while red water cannon trucks were lurking in the background. Protesters who tried to assemble in Cairo's central Tahrir (liberation) Square were manhandled.

In the end, after a meeting with the wife of the president, a typical Egyptian solution was found: one hundred activists were allowed to reach Gaza. The rest remained in Cairo, bewildered and frustrated.

While the demonstrators were cooling their heels in the Egyptian capital and trying to find ways to vent their anger, Benjamin Netanyahu was received in the president's palace in the heart of the city. His hosts went to great lengths to laud his contribution to peace, especially the 'freeze' of settlement activity in the West Bank, a gesture that does not include East Jerusalem. Mubarak and Netanyahu have met in the past - but not in Cairo. The Egyptian president always insisted that the meetings take place in Sharm-al-Sheikh, as far from the Egyptian population centers as possible. The invitation to Cairo was, therefore, a significant token of increasingly close relations.

As a special gift for Netanyahu, Mubarak agreed to allow hundreds of Israelis to come to Egypt and pray at the grave of Rabbi Yaakov Abu-Hatzeira, who died and was buried in the Egyptian town of Damanhur 130 years ago. There is something symbolic about this: the blocking of the pro-Palestinian protesters on their way to Gaza at the same time as the invitation of Israelis to Damanhur.

One may well wonder about the Egyptian participation in the blockade of the Gaza Strip. The blockade started long before the Gaza War and has turned the Strip into what has been described as "the biggest prison on earth". 

The blockade applies to everything except essential medicines and the most basic foodstuffs. US presidential candidate John Kerry was shocked to hear that the blockade included pasta and noodles. The blockade is all-embracing - from building materials to school children's copy books. 

Except for the most extreme humanitarian cases, nobody can pass from the Gaza Strip to Israel or the West Bank, nor the other way round. But Israel controls only three sides of the Strip. The fourth border, the Southern one, is controlled by Egypt. Therefore, the entire blockade would be ineffective without Egyptian participation.

This does not make sense. Egypt considers itself as the leader of the Arab world. It is the most populous Arab country, situated at the centre of the Arab world. Fifty years ago the late Egyptian president Gamal Abd-al-Nasser was the idol of all the Arabs, especially of the Palestinians. How can Egypt collaborate with Israel in bringing 1.5 million brother Arabs to their knees?

Until recently, the Egyptian government had been sticking to a solution that exemplifies the 6000-year old Egyptian political acumen. It participated in the blockade but closed its eyes to the hundreds of tunnels dug under the Egyptian-Gaza border, through which the daily supplies for the population were flowing (for exorbitant prices, and with high profits for Egyptian merchants), together with the stream of arms. People also passed through them - from Hamas activists to brides.

This is about to change. Egypt has started building an iron wall - literally - along the full length of the Gaza border, consisting of steel pillars thrust deep into the ground, in order to block all tunnels. That will finally choke the inhabitants. When the most extreme Zionist, Vladimir Ze'ev Jabotinsky, wrote 80 years ago about erecting an "Iron Wall" against the Palestinians, he did not dream of Arabs doing just that.

Why do they do it? There are several explanations. Cynics point out that the Egyptian government receives a huge American subsidy every year, $2 billion, by courtesy of Israel. It started as a reward for the Egyptian-Israeli peace treaty. The pro-Israel lobby in the US Congress can stop it any time. 

Others believe that Egypt is afraid of Hamas. The organization started out as the Palestinian branch of the Muslim Brotherhood, still the main opposition to the regime. Many people believe that Mahmoud Abbas is interested in the tightening of the Gaza blockade in order to hurt Hamas.

Mubarak is angry with Hamas, which refuses to dance to Egypt's tune. Like his predecessors, he demands that the Palestinians obey his orders. President Abd-al-Nasser was angry with the PLO (an organization created by him, but which escaped him when Yasser Arafat took over). President Anwar Sadat was angry with the PLO for rejecting the Camp David agreement. All these explanations make sense, yet Egypt's attitude is still astonishing. 

The blockade of Gaza destroys the lives of 1.5 million human beings, men and women, old people and children, most of who are not Hamas activists. It is done publicly, before the eyes of hundreds of millions of Arabs, a billion and a quarter Muslims. 

The real answer is probably that Egypt has no choice. Egypt is a very proud country. Anyone who has been in Egypt knows that even the poorest Egyptian is full of national pride and is easily insulted when his national dignity is hurt. That was shown again a few weeks ago, when Egypt lost a soccer match with Algeria and behaved as if it had lost a war. "Consider that from the summit of these Pyramids, forty centuries look down upon you," Napoleon told his soldiers on the eve of the battle for Cairo. Every Egyptian feels that 6000 - some say 8000 - years of history look upon him all the time. 

This profound feeling clashes with reality at a time when Egypt's situation is getting more and more miserable. Saudi Arabia has more influence, tiny Dubai has become an international financial centre, Iran is becoming a far more important regional power. Contrary to Iran, where the Ayatollahs have called upon families to limit themselves to two children, the Egyptian birthrate is devouring everything, condemning the country to permanent poverty. 

In the past, Egypt succeeded in balancing its internal weaknesses with external successes. The whole world considered Egypt as the leader of the Arab world, and treated it accordingly. No more. Egypt is in a bad situation. Therefore, Mubarak has no choice but follow the dictates of the US - which are, in fact, Israeli dictates. That is the real explanation for his participation in the blockade. When I spoke this week at a demonstration in Tel-Aviv against Gaza blockade, I refrained from mentioning the Egyptian part in it. I confess that I liked the people I met during my visits to Egypt very much. The "man in the street" is very welcoming. 

In their behavior towards each other there is an air of tranquility, an absence of aggression, a particular Egyptian sense of humor. Even the poorest keep their dignity in crowded and often miserable conditions. I have not heard them grumble. In all the thousands of years of their history, Egyptians have risen in revolt no more than three or four times.

But a day may come when national pride will overcome even this patience. As an Israeli, I protest against the Israeli blockade. If I were an Egyptian, I would protest against the Egyptian blockade. As a citizen of this planet, I protest against both.

Uri Avnery is an Israeli peace activist. He served three terms in the Israeli parliament (Knesset), and is the founder of Gush Shalom peace movement.