When the Cape Town Opera's revival of "Porgy and Bess" toured Europe, its novel resetting of the American classic to apartheid-era Soweto won raves. When the touring production moved to Israel this month, attention turned sour.

No less than Archbishop Emeritus Desmond Tutu called it "unconscionable" for a South African opera company to perform in Israel, the target of an increasingly aggressive international cultural boycott organized by pro-Palestinian activists hoping to turn Tel Aviv into the new Sun City.

After an ugly public tussle, "Porgy and Bess" — a piece about racism, written by a Jewish composer — opened on schedule Nov. 15, albeit with some hastily added events with Palestinian artists. But protestors outside the Tel Aviv Performing Arts Center still accused the black South African performers of betraying the same kind of boycott that once helped bring down South Africa's apartheid regime.

The showdown capped one of the most combative years yet in Israel's long struggle for international recognition and legitimacy in the cultural world. Buoyed by relative security, an improving economy and a fan base hungry for international acts, Israeli promoters booked an impressive list of big names this year, including Elton John, Rihanna, Metallica, Rod Stewart, Ozzy Osbourne and dance company Alvin Ailey.

But there were plenty of high-profile cancellations too, including Elvis Costello, the Pixies, Carlos Santana, Gil Scott-Heron, Devendra Banhart and a speaking engagement by British film director Mike Leigh.

"We have them on the defense,'' said Ofer Neiman, part of a group of Israeli activists calling themselves the Boycott, Divestment and Sanctions movement, or BDS. Working with Palestinian intellectuals and others around the world, the movement began last year targeting artists who announce plans to perform in Israel. Their strategy includes public protests, picketing at concerts, e-mail and Twitter campaigns and Facebook fan pages, such as one titled " Bob Dylan Boycott Israel." (He hasn't shown up this year.)

Israeli government officials and promoters liken the campaign to "cultural terrorism." Artists increasingly find themselves caught in the middle, faced with the question: to play or not to play.

Boycott supporters say artists' appearances in Israel legitimize what they see as a government policy of discrimination against Palestinians and an ongoing occupation of the West Bank. After pro-Palestinian protesters picketed his London concert this spring, American poet and musician Heron-Scott, known for writing "The Revolution Will Not Be Televised,'' abruptly announced at the end of the show that he'd changed his mind and wouldn't play in Israel "until everyone is welcome there."

Leigh, who is Jewish, cited the Israeli government's recent call for Palestinians to pledge allegiance to a "Jewish state" as the reason for canceling his trip, but he also noted that he hadn't expected how "high-profile" the visit would become.

In a Web message to his disappointed fans, Costello said he backed out because he worried his concert would "be interpreted as a political act that resonates more than anything that might be sung."

Days later, American songwriter Banhart chastised Costello, saying, "What right does he have to deny music lovers the right to music?" and vowing to keep his own concert date. A week later, he backed out too.

Israeli concert promoter Shuki Weiss, whose company booked several of the acts that canceled this year, acknowledged that the boycott has taken a toll. But in his basement office in Tel Aviv, where the walls are decorated with concert posters and rock-star autographs, Weiss said the activists' "guerrilla" tactics amount to "cultural terrorism." He said one California artist, whom he did not identify, canceled after receiving anonymous threats against the artist's children. "They're winning a very lost war and at the end of the day, I think it will backfire,'' Weiss said.

He said a smarter strategy would be to lobby performers to use their celebrity to publicly criticize Israel's policies toward Palestinians. "Surrendering to a boycott just gives the radicals more power,'' he said. "Artists can create change. Music can be a bridge."

Former Pink Floyd bass player Roger Waters, for example, has used his appearances in Israel to criticize the government's treatment of Palestinians and to spray-paint the words "Tear Down the Wall" on Israel's security barrier.

Since its founding, Israel has grappled with cultural and economic boycotts, sometimes rooted in anti-Semitism and other times arising from government policies.

Most recently, a boycott campaign has sprouted inside Israel itself. A group of Israeli actors and writers announced this summer that they would refuse to appear at a new performing arts center that opened this month in Ariel, a large Jewish settlement in the West Bank. Artists say the theater should not be opened in an area where Palestinians hope to one day create a state. Angry conservative politicians are threatening to retaliate by cutting off public funding for artists who refuse to perform in Ariel.

Activists say support for the international boycott began to pick up steam after Israel's 2008 military assault on the Gaza Strip, which killed about 1,400 Palestinians, and was propelled further by the Israeli raid last May against a Turkish ship attempting to get through the naval blockade around Gaza. Nine activists were killed in the raid. Days later, the Pixies announced they would scrap their Israel dates.

Supporting the boycott can also come with a price. Israeli government officials publicly lambasted Costello as "not worthy" of his fans. A pro-Israel supporter in South Africa called Tutu a "bigot."

"It's a complete trap for artists,'' said Beverly Hills attorney Robert Kory, who runs an entertainment management firm. "You get hit from both sides." When his client, Canadian singer Leonard Cohen, got a flood of e-mails last year before his planned concert in Israel, Cohen announced that he would donate all profits to Amnesty International and perform a benefit in the West Bank city of Ramallah.

Activists, led by BDS and the Palestinian Campaign for the Academic and Cultural Boycott of Israel, were unimpressed. Under pressure, Palestinian officials canceled his Ramallah gig and Amnesty declined to accept the proceeds, Kory said. Instead, Cohen used the money to set up a new foundation devoted to Israeli-Palestinian coexistence.

According to activist Neiman, such concessions "don't get artists off the hook." Anyone who crosses the group's international picket line, he said, "needs to be embarrassed."