“Palestinian, Israeli and international BDS activists always try, whenever possible, to appeal to artists in private, and if there is no response, then we go public with our respectful, rational and morally consistent call, largely on social media,” he said in an email to The post. “Mobilizing support from the given artist’s fans and from other cultural figures is key to the success of the appeal.”

A young Jewish woman and a young Palestinian woman in New Zealand wrote a letter to Lorde, published on the website The Spinoff a few days after her concert was announced, appealing to the singer’s sense of social justice, and gently urging her to be “on the right side of history.” It drew her attention, and provided a rare window into her thought process. “Thank u for educating me i am learning all the time too” the singer tweeted before canceling her show four days later. (Lorde’s representatives did not reply to requests for comment for this article.)

If there’s one thing on which both sides can agree, it’s that 21 year-old artists from half a world away can’t be expected to understand the full details of a complicated issue tied to one of the defining geopolitical conflicts of our time. Musicians of any age who contemplate playing Israel sometimes lack awareness of the risks and rewards.

Tour promoters warn acts in advance of any “delicacies they need to be aware of,” says Oren Arnon, a promoter at leading Israeli company Shuki Weiss, who did not promote the Lorde show. Artist managers warn fellow artist managers. David Renzer, a music publishing veteran who co-founded the entertainment industry anti-boycott group the Creative Community For Peace, says his organization works within the record industry to outline the merits of playing in Israel, and warn of its complications.

“Part of what we do is educate them, and say, ‘Guys, you’re going to be hearing from these boycott groups, but there’s things you should be aware of,’ ” he says. “Part of it is an educational process. Once artists go, they tend to have pretty amazing experiences. It’s possible that there may be an artist that just doesn’t want to get harassed. Several artists have come out and said that they felt harassed by boycott groups, and even physically threatened.”

The response to Lorde’s cancellation has been swift, and seismic. A hundred artists, including Brian Eno, Peter Gabriel and author Alice Walker, signed an open letter supporting her. Israel’s Culture Minister said she hoped the singer would reconsider, while its ambassador to New Zealand asked for a meeting. Critics on Twitter pointed out the human-rights abuses in Russia, where Lorde still plans to play two shows. In a roundly condemned full-page ad in The Washington Post, an American rabbi suggested that “21 is young to become a bigot,” its text juxtaposed with an image of Lorde appearing to stare skeptically at the Israeli flag.

Both sides have accused the other of extremist rhetoric, acting in bad faith and bullying, allegations that have become commonplace in the ongoing war for celebrity hearts and minds. Arnon claims Cave, the Australian post-punk icon, endured “months and months of humiliation” before his November shows in Tel Aviv went on as planned. Josh Block, chief executive and president of the Israel Project, a nonprofit group that advocates in favor of Israel, says artists who back out of their concerts are often primarily motivated by a desire to end the controversy. “Lorde, a young kid from New Zealand, announces that she’s going to go to Israel, and within a few minutes, they get this massive onslaught from a highly organized group of extremists. . . . It’s just easier to make it go away.”

The most prominent voice in supporting touring boycotts of Israel has become Pink Floyd co-founder Roger Waters. The man responsible for “Dark Side of the Moon” and “The Wall” has spent the past decade becoming increasingly outspoken on the issue, and uses his fame within the music industry to confront artists who plan to perform in Israel.

In 2006, when the BDS movement was in its infancy, Waters famously played to more than 50,000 people in a chickpea field at Neve Shalom, a cooperative Israeli village that is home to both Jews and Palestinian Arabs; the show was originally scheduled for Tel Aviv. He has since become one of the BDS movement’s most visible spokespeople and a lightning rod for anti-boycott forces, who accuse him of anti-Semitism, a charge he has vehemently denied.

Waters often writes appeals to fellow artists considering playing Israel. Those exchanges don’t always go well. “The Israelis couch it, ‘How brave is Radiohead, to stand up against Roger Waters and his bullying,’ ” Waters says. “What? I had a big email exchange with Thom Yorke. I can’t tell you what was in it, but it was pretty weird. At the end of the day, I have no idea. I cannot begin to explain to you why they did it.”

BDS activists compare performing in Israel to crossing a picket line. Pro-Israel groups say musicians should come to Israel and see for themselves. “When [Jon] Bon Jovi performed, it was important for him to see the Wailing Wall,” Renzer says. “When Justin Timberlake performed, he visited the Wailing Wall and really wanted to feel the power of it, and the same thing with Justin Bieber.”

In 2018, even playing a place like Neve Shalom would be unacceptable, Waters says. “I think those days have gone. I slightly regret that I did that. I kind of forgive myself, because that was 10 years ago, and things have gotten a lot worse since then. I feel like I’ve maybe made amends by such activism as I’ve managed since then.”

Many of Waters’s fellow legacy acts are moving in the opposite direction. Israel attracts a perhaps greater-than-usual share of baby boomers such as Paul McCartney, the Rolling Stones and Elton John. Classic rock acts are often indifferent to social media pressure campaigns, and their fans tend to have enough disposable income to withstand the country’s frequently higher ticket prices.

Emerging concert markets such as Israel represent an opportunity for artists who have come to rely on touring to make up for income lost to dwindling album sales in the new era of streaming. The Israeli concert market has been healthy for almost as long as BDS has been in existence, but it’s impossible to know who is staying away. Artists sometimes scrap concerts that haven’t yet been announced, blame cancellations on nonexistent “scheduling problems,” or, like alt-rock legends the Pixies, cancel shows only to return later.

Promoters live with the constant threat that a musician might bolt, whether it’s an apolitical artist who just wants to avoid a public thrashing, or someone privately sympathetic to the Palestinian cause, observing what Barghouti calls a “silent boycott.” Macklemore & Ryan Lewis, Pharrell Williams, Elvis Costello and Lauryn Hill have all canceled dates in Israel, the latter two suggesting issues of conscience were responsible.

Lorde’s cancellation is seen as a needed, high-profile win for pro-boycott activists. Barghouti cites the Montgomery bus boycotts and the anti-apartheid movement in South Africa as models for the movement, and compares Lorde to Bruce Springsteen, who canceled a North Carolina show after the passage of that state’s controversial “bathroom bill.”

“He engaged in a conscientious act of cultural boycott, just like Lorde did when she canceled her show in Tel Aviv,” Barghouti wrote. Though these are fraught, powerful references — nobody wants to be on the wrong side of a boycott, or apartheid, or Bruce Springsteen — BDS has yet to resonate on a global scale in the way other historic boycotts have. Waters says that while BDS is growing, “It hasn’t taken off like the anti-apartheid movement did. Because that was sort of fashionable, and also there wasn’t a big movement trying to stop it.”

Although no one knows yet whether Lorde’s decision is an isolated event or the beginning of a cascade of similar cancellations, activists such as Waters view her decision as a pivotal moment for the BDS movement. “She must be quite bright, because she looked at the situation and went, ‘Wow, no, I cannot nail my colors to that mast,’ ” he says. “And so she’s hugely important. If I could find three or four or five of those in my generation — they’re there, they’re just a bit limp-wristed. I know a few of them, but they won’t stand up and go, ‘I’m BDS,’ and until they do, we will go on growing without them.”

Lorde will almost certainly be one of the last major artists to schedule an Israel concert date without appearing to have fully considered the global implications. From now on, if it weren’t the case already, merely scheduling a concert date in Israel will be considered a political act.

“It’s a very tricky issue,” the concert promoter Arnon says. “And you never come out of it clean.”