For more than a hundred years Arabs and Jews have been killing each other in Palestine\Israel. It has become something of a routine; except for the families involved, the killings, sadly, lack real significance. Same old, same old.

But last Sunday's murder was something else, and infinitely depressing. Julian Mer-Khamis, born in Israel to a Jewish mother and a Christian Arab father, was hit by five bullets as he was driving through the Jenin refugee camp, in the West Bank, where – for much of his time – he lived and worked. The 52-year-old actor and director had managed the Jenin "Freedom Theater," where Palestinians, many of them from the camp, were given a glimpse of a different world.

He was probably shot by an Islamist (though no one has yet "claimed" the assassination). The town's conservative Muslims for years have denounced the theater and called for its closure because men and women, boys and girls, mixed on stage and in the audience, and by-Muslim-standards risque plays were often the fare (nowadays it was "Animal Farm," an adaptation of Orwell's novel, which lambasted dogmas, the herd instinct and absolutism – and where actors of both sexes, dressed as pigs, unclean animals in both Islam and Judaism).

The Islamists may also have resented Mer-Khamis's "Jewishness" – he had been raised in Israel and had done his IDF service in the paratroops.

But in the past two decades Mer-Khamis had drifted, in identity and ideology, into the Palestinian camp. Of late, he had explicitly supported "armed resistance" to the Israeli occupation, "by any means," and called for a "one-state [solution] between the [Jordan] River and the [Mediterranean] Sea," meaning that he opposed Israel's continued existence as a Jewish state and the idea of a partition of the country in a two-state solution. "If the Jews want to live among us [Arabs], ahalan wasahalan [they are welcome]," he told journalists. But these well-publicized views, anathema to almost all Jewish Israelis, proved insufficient to appease the murderous Islamists.

Mer-Khamis may also have believed that he was "protected" by the patronage of the former head of Jenin's Al-Aksa Brigade branch, the Fatah-sponsored militia, Zakariya Zbeidi. Zbeidi, who downed arms a few years ago, served as the theater's a co-manager, giving Mer-Khamis and the whole enterprise a patina of legitimacy. Zbeidi is a Palestinian resistance icon: Shot and imprisoned by the Israelis during the First Intifada, he had been one of the Second Intifada's symbols, for years successfully evading Israeli hit squads and drones.

And, of course, Jenin itself was one of that Intifada's symbols. A disproportionate number of suicide bombers set out from the town into northern Israel, wreaking havoc among the Jews. In turn, when Israel struck back, in 2002, taking the town, one of its reserve brigades suffered some two dozen dead in the conquest of the refugee camp, much of which was levelled in the process. The Palestinians, as is their wont, at the time screamed "massacre, massacre" – but the charge was denied by Israel and refuted, too, by such neutral bodies as Human Rights Watch, which said there had been only a handful of civilian deaths on the Arab side during the battle, which also claimed the lives of some 50 Arab combatants.

Mer-Khamis's death had in a way closed a circle. His mother, Arna Mer, also a peace activist, in the 1980s, had set up and run a children's theater in Jenin. Zbeidi had then been one of her child-actors. Mer-Khamis founded the Freedom Theater in 2006.

The murder casts a bleak light on prospects for Israeli-Palestinian peace. Many Israelis and some Palestinians may talk about eventual peace. But Mer-Khamis, who embodied Israeli-Arab co-existence, splitting his life between Haifa and Jeninin in the end fell victim to those who would uproot both Israel and the Jews from the country, those who won the Palestinian parliamentary general elections in 2006. What the murder tells Israelis is that whatever moderate, or pretend-moderate Palestinian voices enunciate, peaceful intent and propagation will always, ultimately be drowned out, and overpowered, by the fundamentalist true believers and their Brownings.