When Massachusetts Institute of Technology professor Nancy Kanwisher helped launch a spring petition calling on Harvard and MIT to cut their financial ties to Israel, she saw it as a political protest against Israel's alleged violation of Palestinians' human rights.
But in the months since she helped gather signatures on the two campuses, her effort has become the target of a much larger counterpetition - and, this week, a high-profile denunciation by Harvard president Lawrence H. Summers, who declared her group's actions "anti-Semitic in effect, if not intent."
After his stinging speech, divestment was once again in the spotlight, as students and faculty debated yesterday whether it is possible to protest Israel without evoking the grim legacy of anti-Semitism.
"Harvard prides itself on academic freedom, but the question of punishment against Israel is tricky and divisive for people," said Rohit Chopra, a junior who chairs the student affairs committee of the Undergraduate Council. "It's so super-sensitive because Israel is a home or a second home spiritually to so many people. So it's hard to criticize Israel delicately and avoid a tough label like anti-Semitism."
Kanwisher was direct in her reaction. Summers "should be ashamed of himself," she said, "casting these McCarthy-esque insinuations about our motives."
Summers declined to comment yesterday. But some Harvard professors who have asked him about his speech said Summers assured them he was not personally labeling the signers of the petition as anti-Semitic.
The Israeli divestment idea was born two years ago in a speech by University of Illinois professor Francis A. Boyle, who says he hoped to influence Israeli policy in the same way the 1980s South African divestment campaign helped end apartheid.
Boyle had studied human rights law at Harvard. At the time, he also joined calls for Harvard to withdraw its investments in South Africa - which the university eventually did.
To Boyle, the divestment issue is exactly the same in both instances, legally and morally.
"Israel clearly practices apartheid against Palestinians," he said. "This isn't reinventing the wheel."
But a protest against Israel, a close ally of the United States whose modern roots are entwined with World War II atrocities against Jews, has proved a far more loaded issue on American campuses.
"Why don't they say anything about Cuba's chilling of dissent or China's occupation of Tibet? Why don't they feel a personal stake in getting Jordan, Egypt, and the Philippines to stop torturing people?" asked Harvard law professor Alan Dershowitz, who said he would resign if Harvard divested from Israel. "The only reason they feel so strongly about Israel is because it is the Jewish nation."
But the divestment proponents point out that the US government sends more money to Israel than those other countries - about $3 billion a year. And their petitions assert that Harvard has some $600 million invested in US companies that do business in Israel.
Mary C. Potter, a professor of cognitive sciences who started the MIT petition with Kanwisher, doesn't regret sparking debate. But she's aghast at the anti-Semitism charges. Although she still believes in the goals of divestment, she has begun to wonder what role non-Jews can play in the debate.
"Change will have to come from Jewish groups, because they cannot be accused of anti-Semitism," Potter said.
At Princeton University, where a divestment petition began circulating last spring, a student leader of the campaign renounced the cause publicly.
"I came to the realization not only that it was impractical but that it is divisive in that the tactic isolates one group - Jews and Israeli people," said Taufiq Rahim, who is Muslim and hails from Vancouver. "Many Jewish, Israeli, and Palestinian people are interested in the same things."
Rahim, who had gathered signatures for the campaign, wrote a letter to faculty members explaining his switch. He still opposes Israeli occupation of the West Bank and Gaza.
The Princeton petition inspired the Cambridge activists. Potter and Kanwisher and some friends at Harvard were looking for a way to put into action their opposition to Israeli Prime Minister Ariel Sharon. Kanwisher was "desperately casting around on the Web one night to see what other people were doing," when she found a Web page for the Princeton divestment campaign.
The petition said signers are "appalled by the human rights abuses against Palestinians at the hands of the Israeli government." It also called attacks on Israeli citizens "abhorrent."
Circulated by e-mail, it garnered 69 signatures from Harvard faculty and 55 from MIT faculty. But it also sparked a much larger countersalvo - a new petition calling the divestment campaign "a one-sided attempt to delegitimize Israel," and saying it "revives rhetoric long discredited by its use among extremists as code for the destruction of the Jewish state."
That counterpetition was signed by 439 Harvard faculty and 143 MIT faculty.
The local divestment activists' next plan is to try to book some speakers on the topic. On a national level, a conference at the University of Michigan in October will discuss how to bring the issue to new campuses. Boyle, the Illinois professor, said he believes that minds can be changed.
"I would hope there could be a dialogue between us and President Summers," he said.
Patrick Healy of the Globe Staff contributed to this report.