The day before yesterday the Haaretz headline screamed: "Doctors: Arafat died of Aids or poisoning". Aids appeared in first place.

For dozens of years, the Israeli media has conducted, with government inspiration, a concentrated campaign against the Palestinian leader (with the sole exception of Haolam Hazeh, the news magazine I edited). Millions of words of hatred and demonization were poured on him, more than on any other person of his generation. If somebody thought that this would end after his death, he was mistaken. This article, signed by Avi Isasharof and Amos Harel, is a direct continuation of this smear campaign.

The key word is, of course, "Aids". Throughout the long article there is no trace of proof for this allegation. The reporters quote "sources in the Israeli security establishment". They also quote Israeli doctors "who heard from French doctors" - an original method for medical diagnosis. A respected Israeli professor even found conclusive proof: it was not published that Arafat had undergone an Aids test. True, a Tunisian medical team did test him in Ramallah and the result was negative, but who would believe Arabs?

Haaretz knows, of course, how to protect itself. Somewhere in the article, far away from the sensational headline, there appear the nine words: "The possibility that Arafat had Aids is not high". So Haaretz is alright. In army parlance, its ass is covered. By comparison, the New York Times, which published a similar story on the same day, treated the Aids allegation with contempt.

There is a very simple proof for the spuriousness of the allegation: if it had even the most tenuous basis in fact, the huge propaganda apparatus of the Israeli government and the Jewish establishment throughout the world would have trumpeted it from the rooftops, instead of waiting for 10 months. But, as matter of fact, there is no evidence whatsoever. More than that, the writers themselves are compelled to admit that Arafat's symptoms are completely incompatible with the picture of Aids.

So what did he die of?

Since taking part in his tumultuous funeral in Ramallah, I have abstained from giving my opinion on the cause of his death. I am not a doctor, and my dozens of years as editor of an investigative news magazine have taught me not to voice allegations which I am unable to prove in court.

But, since now all dikes have been breached, I am prepared to say what is on my mind: from the first moment, I was sure that Arafat had been poisoned.

Most of the doctors interviewed by Haaretz testified that the symptoms point towards poisoning, and, in fact, are incompatible with any other cause. The report of the French doctors, who treated Arafat during the last two weeks of his life, states that no known cause for his death was discovered. True, the tests did not find any traces of poison in his body - but the tests were conducted only for the usual poisons. It is no secret that many intelligence services in the world have developed poisons that cannot be detected at all, or whose traces disappear in a very short time.

Some years ago, Israeli agents poisoned the Hamas chief Khaled Mash'al with a slight prick in a main street of Amman. His life was saved only because King Hussein demanded that Israel immediately provide the antidote. (As a further indemnity, Binyamin Netanyahu agreed to the release from prison of another Hamas chief, Sheik Ahmed Yassin, who was assassinated several years after his return to Gaza by more conventional means - an airborne missile.)

In the absence of symptoms of any known disease, and since clear indications of poisoning were present, the highest probability is that Yasser Arafat was indeed poisoned while having dinner four hours before the first symptoms appeared.

I can testify that the security arrangements around the Ra'is were very lax. At each of my dozens of meetings with him in different countries I was always amazed at the ease with which a potential assassin could have done his job. Protection was always casual, especially compared to the way Israeli Prime Ministers are guarded. He often had his meals in the company of strangers, he embraced his visitors. Associates report that he frequently accepted sweets from strangers and also took medicines from visitors, swallowing them on the spot. After surviving dozens of assassination attempts, and even an airplane accident, he had come to adopt a fatalistic attitude, "it's all in the hands of Allah". I think that in his heart of hearts he really believed that Allah would preserve him until the completion of his historic mission.

If he was poisoned - by whom was he poisoned?

First suspicion falls, of course, on the Israeli security establishment. Indeed, Ariel Sharon declared on several occasions that he intended to kill him. The subject came up in cabinet meetings. Twice during the last years my friends and I were so convinced that this was imminent, that we went to the Mukata'ah in Ramallah to serve as a "human shield" for him. We were convinced that the murder of Arafat would cause much harm to Israel. In one of his interviews, Sharon stated that our presence there had prevented his liquidation.

Truth is that Sharon abstained from killing Arafat mostly because the Americans forbade it. They were afraid that the murder would arouse a huge storm in the Arab world and exacerbate anti-American terrorism. But this interdiction may have applied only to an overt act.

The Mash'al affair proves that the Israeli intelligence services have the means to poison people without leaving any trace. The poisoning was discovered only because the perpetrators were caught in flagrante.

However, a probability, high as it may be, is not proof. At the moment, there is no proof that Arafat was indeed poisoned by the Israeli services.

But if not the Israelis, who? The US intelligence services also have the necessary capabilities. President Bush never hid his hatred for Arafat, an obstinate leader who did not submit to his dictates. He was quick to embrace Mahmoud Abbas. Even now, American emissaries who visit the Mukata'ah pointedly abstain from putting wreaths on the grave of the Ra'is in the courtyard.

But American interests, too, do not constitute proof. One can think of several other suspects, even in the Arab world.

Did Arafat's death benefit Sharon?

On the face of it, no. As long as Arafat was alive, American support for Israel was unlimited. But since his death, President Bush has been going out of his way to support his successor. The dismal American debacle in Iraq compels Bush to look for achievements elsewhere in the "Broader Middle East". He presents Mahmoud Abbas as a symbol of the new winds blowing through the Arab and Muslim world as a result of American policy. In order to convince the Palestinian public to support Abbas, Bush is putting pressure on Sharon of a new sort. Perhaps Sharon is secretly longing for the good old days of Arafat, when life was simple and an enemy dressed the part.

But a person who wants - as Sharon surely does - to break the Palestinian people into pieces and prevent at any cost the establishment of a viable State of Palestine, can only be happy with the demise of Arafat, who united the entire Palestinian people. He had the moral authority to impose order, and he enforced it by empathy and force, human wisdom and tricks, threats and seduction.

There are many people in Israel who hoped that without him the Palestinian society would break apart, that anarchy would destroy its very foundations, that armed factions would kill each other and the national leadership. They are certainly glad that Arafat is dead and pray for the failure of Mahmoud Abbas.

Arafat assured me once that we would both see peace in our lifetime. He was prevented from seeing the day. He who caused this - whoever he is - has sinned not only against the Palestinian people, but also against peace, and therefore against Israel.