NEW DELHI — A lynching is much more than just a murder. A murder may occur in private. A lynching is a public spectacle; it demands an audience.

The lynching of Pehlu Khan, a 55-year-old dairy farmer, in the western Indian state of Rajasthan at the beginning of this month attracted a live audience of dozens and a virtual one in the millions. Mr. Khan, a Muslim, stood accused of smuggling cows, which are sacred to Hindus. A whole nation watched the scene on its smartphones and televisions: Mr. Khan, a lone hunted figure in white, lurches and stumbles along the edge of a dusty highway. He is pursued by “cow vigilantes,” young men in striped T-shirts and jeans, armed with belts and sticks. Eventually they gain on Mr. Khan, who falls to the ground, clutching his stomach. A crowd with cameras and smartphones circles. In screen within screen, we see Mr. Khan brutally beaten by the vigilantes in broad view of everybody. He died three days later, the sixth fatality since 2015 of a Muslim man subjected to vigilante justice of this kind.

A lynching, unlike, say, a terrorist attack, does not depend on maximizing the loss of life. What matters — whether in the American South a century ago or in India today — are not numbers, but the public, almost orgiastic character of the violence. The crowd surrounding Mr. Khan was baying for him to be doused in gas and set alight. A lynching is a majority’s way of telling a minority population that the law cannot protect it. That is why in the American South so many African-American men were dragged from jails or hanged outside courthouses — unmistakable symbolism of the law’s paralysis.

In Mr. Khan’s case, the law was not merely paralyzed; it actively served the killers. In the first hours after Mr. Khan was attacked, 11 people were rounded up and arrested for cow smuggling — but not one for murder. Three people were arrested for Mr. Khan’s lynching, but only days later, after he died. But the effect of the arrests was minimized by the role played by Prime Minister Narendra Modi’s Bharatiya Janata Party.

The home minister of Rajasthan, the official in charge of the state’s law enforcement, went on national television a few hours after Mr. Khan died to make clear where his sympathies lay. First, he played down the incident, describing it as “manhandling,” then he seemed to urge the public to show understanding to the killers’ motives: “There are two sides to this,” he said.

Mukhtar Abbas Naqvi, Mr. Modi’s minister of state for parliamentary affairs, went even further: He said the incident never took place at all. Mr. Modi and Vasundhara Raje, the chief minister of Rajasthan, have yet to offer one word of either condemnation or condolence.

The active ingredient in a lynching is silence. Like all forms of theater, a lynching depends on what is left unsaid; it creates a mood, an atmosphere. The silence that settles in after the euphoric act of violence, which all have witnessed, tells a minority group that it has been forsaken. It is this element of a suggestive and creeping threat, in which the state apparatus and a silent majority are complicit, that has the power to demoralize a community as much as the physical acts of violence.

The hysteria that now surrounds the cow in India has been engineered. It was Mr. Modi who, during his election campaign in 2014, whipped crowds into frenzy over “a pink revolution,” an alleged conspiracy by his political opponents to promote cow slaughter and beef export. “We’ve heard of the Green Revolution,” he thundered, “we’ve heard of the White Revolution, but today’s Delhi government wants neither; they’ve taken up arms for a Pink Revolution,” he said, presumably evoking the pink color of beef. “Do you want to support people who want to bring about a Pink Revolution?”

It took Mr. Modi almost a year after the first lynching, in September 2015, to clearly and firmly denounce the cow vigilantes. But the prime minister is a master at looking both ways when it comes to mob violence. Last month, after a landslide electoral victory in the northeastern state of Uttar Pradesh — where almost a quarter of India’s roughly 170 million Muslims live — he appointed a vicious priest, in full saffron robes, to be the state’s chief minister.

That man, Yogi Adityanath, has called for the family of the first lynching victim to be tried for illegally storing beef in their home. He has exhorted his followers to kill 10 Muslims for every Hindu killed. No sooner did he become chief minister than Mr. Adityanath led a crackdown against unlicensed butchers and abattoirs. Uttar Pradesh abounds in unlicensed businesses, but in singling out the meat industry — invariably run by Muslims — the politician-priest knew that he was in effect leading an attack on Muslim business with shades of Kristallnacht.

B.J.P. chief ministers across India are now falling over themselves in a quest to outdo one another in showing their love of the Indian cow, which, as Mr. Khan’s killing demonstrates, is animated partly by a hatred of Muslims. Last month, in Mr. Modi’s home state of Gujarat, cow slaughter was made punishable with life in jail; and in Chattisgarh, another B.J.P.-run state, the chief minister announced, “We will hang those who kill cows.”

Almost 60 percent of India now lives in B.J.P.-controlled states; there is no opposition left to speak of. What voices of moderation and reason there used to be within the B.J.P. are either too cowed to speak or feel that it is politically inexpedient to do so.

Vasundhara Raje, the chief minister of Rajasthan, is someone I grew up around in Delhi and have known all my life. She is aristocratic and is educated. She had many Muslim friends and even a Muslim boyfriend. She was a single mother, like mine. She smoked, she drank; she is well read and widely traveled. She certainly seemed the beneficiary of liberal values. That someone like her would now refuse to speak up for a poor Muslim farmer with small children who was lynched in her state is an indication of how poisoned the air has become in three short years since the B.J.P. came to power.

India is slipping beyond the pale. It is unfathomable that the ancient Hindu horror at the taking of life, any life — the very same doctrine of ahimsa, or nonviolence, that governed the beliefs of men like Mahatma Gandhi and the Rev. Dr. Martin Luther King Jr. — should in our time be used as a justification for murder. And not merely a murder in which one man is implicated, but rather a great televised spectacle in which a whole nation, through its silence, is complicit.