I first met Kamal Medhat, whom I always knew as Kamal Naji, in early 2007, when I was looking for background information to review a book on militant Islam in the Ain al-Hilweh Palestinian refugee camp. At the time, Kamal could still claim to have abandoned everything for the attractions of academia, though you knew even then that the finality of the man was not a fastidious thesis and a chalkboard.

Kamal had been an aide to Yasser Arafat in the 1980s and was the official who surrendered the Palestinians' heavy weapons to the Lebanese government in 1991, when the army, backed politically by Syria, attacked Palestinian forces east of Sidon. When Abbas Zaki was named the Palestinian Liberation Organization's representative in Lebanon after the Syrian pullout in 2005, he chose Kamal as his deputy. Zaki needed a man with experience and decisiveness on the ground. He also used him as a counterweight to the secretary of the Fatah movement in Lebanon, Sultan Abu al-Aynayn, whose allegiances, typical of a Palestinian official who had to maneuver through the years of Syrian domination, were complicated when it came to the Ramallah-based Palestinian Authority.

The speculation over who killed Kamal Medhat will continue for some time. Hamas is a prime suspect, however that theory doesn't seem particularly credible. That's not because the Islamist movement is incapable of such a thing, but because in Lebanon Hamas probably doesn't have the political latitude or wish to take such a drastic measure, which risks a major backlash. The identity of the murderers in such cases does not remain secret for very long. That doesn't mean that Hamas will not benefit from Medhat's elimination, but it seems more likely that others calculated that consequence on the movement's behalf.

Was Syria involved, or Hizbullah, or a cutout acting on behalf of one or the other? That's possible; both have an interest in marginalizing the Palestinian Authority led by Mahmoud Abbas, which means weakening Fatah and undermining the independence of Palestinian decision-making in Lebanon. However, men like Medhat stand at the nexus point of complex relationships, where political, security, and intelligence interests intersect, buried in layers of ambiguity, so that while it may be tempting to jump to obvious conclusions, the truth may be more complex. Soon enough we will have a better sense of what happened, but until then what are the broader consequences of Kamal Medhat's assassination?

It is surely no coincidence that Medhat was killed at a particularly sensitive moment in the negotiations over a Palestinian-unity government in Cairo. Those talks have gone nowhere in recent weeks, which is hardly a surprise. Neither Syria nor Iran is eager to cede to Egypt a diplomatic victory on the Palestinian front, or to lay the diplomatic groundwork for a revival of the Saudi peace plan adopted by the Arab League in 2002. As the Doha Arab summit looms next week, the struggle over who holds the Palestinian card seems to be intensifying, with Syria and Iran, each for reasons of its own, wanting to ensure that it can veto, through Hamas, any possible consensual Arab policy on Palestinian negotiations with Israel.

Does Medhat's killing signal the final nail in the coffin of the troubled Palestinian unity talks? Not necessarily. In fact it may be an upping of the ante to soften Fatah's stance by sending the movement a warning that the next battlefield between it and Hamas will be the Palestinian refugee camps in Lebanon. Who has the advantage? Since Hizbullah is bound to oppose Fatah, and the Lebanese state will undoubtedly be too timorous to take sides in an inter-Palestinian confrontation, particularly if Syria prevents it, Fatah may find itself under increasing duress, allowing Hamas and pro-Syrian Palestinians to regain the initiative in the camps.

Fatah retains much support among the Palestinians in Lebanon, and it's not the murder of Kamal Medhat that will reverse this. However, if Fatah's leadership comes under more attack and is unable to distribute money and services in the way it has managed to in the past year, and is unable to protect its political independence and Ramallah's sway in the camps, the balance may slowly shift away, perhaps even within the movement. The Syrians, for example, may be more comfortable with the Fatah leadership in place before Zaki arrived, over which it had greater influence.

Doha will determine whether the so-called moderate Arab states have any valid rejoinder to the very plain Syrian and Iranian efforts to hijack the Palestinian cause. It's no secret that Hamas leaders would like to take control of the PLO away from Fatah, just as it's no secret that Syria tried during the Gaza war to persuade other Arab states to distance themselves from the 2002 Arab peace plan. Damascus prefers to talk to Israel alone, so that it is not blindsided by parallel progress on the Palestinian track; and with Hamas these days largely doing Syrian and Iranian bidding, the Syrians are in a position to strengthen their bargaining hand by manipulating Palestinian affairs. The late Yasser Arafat spent three decades trying to avoid that situation. It's no wonder, then, that Medhat, once one of his collaborators, should have paid so high a price.

In that context, doesn't the Saudi-led project to renew Arab amity risk creating an opportunity for Syria, and with it Iran and Hizbullah, to cripple an autonomous Palestinian track led by Mahmoud Abbas? More perniciously, isn't this precisely what a government led by the next Israeli prime minister, Benjamin Netanyahu, would welcome? Netanyahu and Syria's President Bashar Assad share a longing to discredit Abbas. A strengthening of Hamas would allow Netanyahu to say that he has no Palestinian interlocutor, which would allow Assad to respond: "Well, you will always have Syria to talk to."

We don't yet know who killed Kamal Medhat, and who is targeting an independent Fatah in Lebanon. But we can say who stands to gain from this, whether they were involved in the crime or not. Pity the Palestinians for once being a powerful idea now in serious risk of becoming an afterthought.