By Paul Adams
BBC News, West Bank
The latest violent upheaval in Gaza has left the Palestinians with little chance of an easy reconciliation.
"The Palestinians must remain united," Abu Amjad said. But his haunted face told a different story.
Tension between Fatah and Hamas dates back to the mid 1990s
The car which brought him to our rendezvous in Ramallah bore the conspicuous emblems of Fatah. A black and white chequered scarf hanging from the rear-view mirror. A yellow flag flying from the aerial.
Such overt displays are fine in a town where Fatah rules the roost, but Abu Amjad is still scared. He agreed to be interviewed only if we disguised his name, face and voice.
Anything but yellow
He had fled Gaza with his wife and children two days earlier. At the height of the fighting, he had heard Hamas militants issuing chilling orders on their walkie-talkies and seen dead bodies in the street.
His children were scared, and started to speak only in whispers. When they asked for toys or sweets, they demanded anything but yellow. In Gaza, everyone, even the smallest child, knows that a simple colour can get you in trouble.
When Abu Amjad saw a group of gunmen on his own roof and realised he was being followed, he decided it was time to leave. His brother, a prominent Fatah official, is still in Gaza. Hence Abu Amjad's reluctance to be identified.
One small detail confused me. He said Hamas gunmen had checked ID numbers before deciding what to do with people. Anyone whose number began with a four was suspect.
Why? Because that is how Israel, which granted the permits, signified any Palestinian who returned from abroad after the Oslo peace accords in 1993. And the largest number of these belonged to Yasser Arafat's Fatah faction.
Here, in this innocent little digit, was one clue as to why the Palestinian struggle had turned in on itself. Why it had become a kind of revenge tragedy, in which bloody events unfold against the backdrop of a social and political order in tatters.
In 1994, when Yasser Arafat returned in triumph to the Gaza Strip after decades in exile, the PLO, with Fatah at its head, was on the road to national redemption. But as they returned, Arafat's men appeared to forget that there were other Palestinians already in the Palestinian territory.
Desire for revenge
Men and women who had already fought their own first intifada paid a heavy sacrifice in blood, and forced Israel to take them seriously. Move aside, the newcomers seemed to say. We are in charge now. Leave it to us.
For Gazans and West Bankers - secular and religious activists alike - this was galling. When the newcomers began to flaunt their new-found wealth, building ostentatious villas in one of the poorest places on earth, disillusion quickly set in.
And there was brutality too. Hamas activists were hounded, arrested, beaten and humiliated.
A bitter desire for revenge began to fester.
Hamas militants set up makeshift checkpoints in Gaza City
And imagine how much keener that desire became after Hamas won a democratic election in January 2006, only to see that Fatah's disdain persisted.
Hamas had not really expected to find themselves suddenly in power. They wanted, rather, to be regarded as a legitimate part of the Palestinian movement.
But Fatah assumed that in time, its rivals would be crushed. Israel, through air strikes and mass arrests, worked hard to achieve this.
'No plan to rule'
The international community shunned Hamas because of its association with terrorism, despite being advised by many on the ground that constructive engagement might be a more profitable course of action.
Hamas supporters, not surprisingly, became convinced that they were the targets of an international conspiracy designed to destroy them.
You will hear wildly conflicting accounts of who started what in Gaza, but none of this really matters now. What does matter is that Hamas won and, in the process, trashed all those vulgar villas and everything else that spoke of Fatah's misrule.
But just as Hamas was startled by its victory at the ballot box, now it seems its gunmen are equally surprised at how easy it was to win the military battle.
A friend of mine in Gaza, welcoming the fact that the streets are now safer than they have been for two years, told me Hamas is in a quandary. They simply have no plan to rule, he told me. They do not even want to rule.
But if Hamas is waiting for Fatah to come back, cap in hand, suing for peace, then it is going to be disappointed. On Tuesday, Fatah's central committee cut off all contacts with Hamas.
For now, the desire for retribution is too strong and will, I fear, only make things worse.
While in Ramallah, I visited the house of a prominent Hamas politician, Abdel Aziz Dweik, fire-bombed at the dead of night. There was no-one inside. Mr Dweik has been languishing in an Israeli jail for the past year. But the shattered glass and soot-stained walls looked ugly enough.
"Reconciliation? After all this? No," said Abu Amjad. "Because no-one can forget the blood, especially when it has been shed by your own brothers. We are one people, but right now we are sailing in two ships, in opposite directions."
From Our Own Correspondent was broadcast on Saturday, 23 June, 2007 at 1130 BST on BBC Radio 4. Please check the programme schedules for World Service transmission times.