<< Buddhist monks and nuns of Shugden Society demonstrate against the Dalai Lama in front of New York's Radio City Music Hall Thursday, July 17, 2008.
Ed Ou / AP

There were no arrests, but the police felt it prudent to move in fast and herded the smaller group into buses for their own protection. The pro-Dalai Lama crowd had also flung money at their foes, an insult indicating that they had been bought (presumably by the high lama's enemies in Beijing).

Said one of the anti-Dalai Lama protesters, Kelsan Norden, who is British, has a Tibetan name and is the spokeswoman for the Western Shugden Society, "If this is what the Dalai Lama's people do to us in America, can you imagine what they would have done somewhere else?" The combination of adrenaline, relief and the prospect of coverage left her sounding almost elated.

What had prompted the unnerving Buddhist-on-Buddhist confrontation was an intra- Tibetan problem that seems poised to go international. The protesters, devotees of a fierce "protector deity" called Dorje Shugden, claim that the spiritual leader of Tibet has curtailed their civil rights as part of a religious vendetta. For now, the allegations of the Shugdenpas (as they are known) are hard to prove or disprove. But even a brief investigation provides a vivid look into what experts call "the shadow side" of Tibetan Buddhism, contrasting the tolerance and rationalism that the Dalai Lama represents globally and the theological hardball over mystical principles that he seems to play on his home turf.

Dorje Shugden is one one of hundreds of "protector deities" that distinguish Tibetan Buddhism from more purely philosophical varieties. Historically, the god is associated with the maintaining, sometimes violently, the purity of Dalai Lama's own lineage of teachers and gurus, called the Gelugpa. Indeed the high Lama himself prayed to Shugden for years; but the sect's purist and exclusionary emphases contradicted his own outreach to other Tibetan lineages, and in 1996 he began demanding that monastic abbots renounce the deity.

Those who did not suffered consequences, although how dire is yet unclear. Shugdenpas have long claimed to have been shunned and harassed. A 1998 Amnesty International report indicated that the complaints were exaggerated. The sect suffered a public relations setback in 1997, when Indian police named two of its practitioners as suspects in the ritual slaughter of one of the Dalai Lama's close associates, seeming to confirm (although the suspects have never been tracked down or tried) the worst suspicions of critics.

Yet Shugden practitioners deny that they are fundamentalist, purist or violent, and have renewed their complaints in light of an intensifying crackdown by the Dalai Lama. He — or people acting in his perceived interests — has expanded the loyalty demand from abbots to monks and even laypeople as far afield as France. In a nod to the Tibetan Government in Exile's self-definition as a democracy, each monastery has been taking a referendum on Shugden. When the "anti" faction inevitably wins, the monks pledge to renounce Shugden and deny spiritual or material aid to those who hold out. In transcripts that Shugdenpas allege record the Dalai Lama's comments, he sounds atypically authoritarian. "Shugden devotees are growing in your monastery," he is quoted as snapping at one abbot "If you are this inept, you had better resign."

What pushes the current allegations into a potential human rights matter is the contention that those who won't take the oaths are denied monastery I.D. cards that the Tibetan Government in Exile allegedly requires to process visa requests through to the Indian government. (Most of the Tibetan diaspora lives in India.) "Families are being torn apart," reads Shugden literature.

Tashi Wangdi, the Dalai Lama's American representative, denied the allegations. "I have heard about the [I.D.s]," he said. "But as far as official policy goes, there's no discrimination." Regarding the oath to give no assistance, he said "I am sure that no Tibetan government administration office has asked anyone to sign this document." However, he notes, "It is within the rights of individual organizations to have conditions that they stipulate for members."

The problem is that in Tibet most people shun whom they think the Dalai Lama wants them to shun. The protesters display photos of signs they say have gone up recently in Tibet urging shopkeepers not to do business with tainted monks. They could be written by anybody, but most people assume they know the ultimate author of the signs.

Experts seem to think that there is something to the Shugden allegations. "There is considerable anecdotal evidence to support what they say," Stephen Batchelor, co-founder of the Sharpham College for Buddhist Studies and Contemporary Enquiry, wrote in an email to TIME, although, he adds, "I have yet to see any hard evidence." Robert Barnett of Columbia University, adds "I bet it is a lot easier to get a visa if you have an exile official at your side."

Norden, the Shugden spokesperson, observes correctly that even if the Dalai Lama is not behind the current Shugden woes, "if he wanted it to stop, all he'd have to do would be to snap his fingers." Yet no-one expects that. Most scholars e-mailed for this story were hesitant to line up behind the Shugdenpas; partly because of insufficient data; partly, perhaps, because of a feeling that this was a Tibetan issue ("these are monk wars," said one); partly because many are themselves deeply invested in the Dalai Lama; and partly because of the whiff of fundamentalism and recklessness that clings to the sect. Shugden "is about vengeance," says Columbia's Barnett. "I think that any talk of [its devotion to] compassion is misleading." Barnett believes that the movement's true goals must be "brought out into the open" — especially to innocent Westerners — before "the real social concerns that must exist" in Tibet can be addressed.

"People see hope in the Dalai Lama," says Shelley Turner, another protester spokesperson, with some empathy. "Seeing these protests against him must make them feel hopeless." She means, when they finally hear the harsh truth about him. Others surely believe the truth is on his side.