The violent death of an American missionary on a remote island in the Indian Ocean in mid-November raises new and urgent questions about the survival of uncontacted and isolated tribes and their right to remain free from interference from the outside world.

John Allen Chau, 26, a self-described “adventurer” from Vancouver, Washington, sought to convert a reclusive tribe to Christianity, trespassing on North Sentinel Island to do so.

View Images Administered by India and strictly off-limits to outsiders, coral-fringed North Sentinel Island has been home to the Sentinelese tribe for thousands, possibly even tens of thousands, of years. Photograph by Gautam Singh, AP

The coral-fringed island, which is about the size of Manhattan and strictly off-limits to outsiders, harbors one of the planet’s most isolated hunter-gatherer societies, known as the Sentinelese. North Sentinel is part of the Andaman and Nicobar Islands, a sprawling archipelago administered by India that stretches between India’s southern tip and the west coast of Myanmar.

No one knows for sure how long the Sentinelese—the last demographically intact, essentially uncontacted tribe of the Andamans—have lived there, but some studies indicate the tribe may have migrated from Africa tens of thousands of years ago.

Like uncontacted and isolated tribes elsewhere in the world, most notably in the Amazon rain forest, the Sentinelese are considered to be at high risk for contagious diseases borne by outsiders, against which they have little or no immunological defense.

The Sentinelese are deft archers who have developed a fearsome reputation as staunch defenders of their homeland. Believed to number no more than a hundred, they’re the sole inhabitants of the densely forested island. Previous attempts at contact have been met with showers of spears and arrows.

View Images John Allen Chau, an American missionary and self-described "adventurer," stands with Casey Prince, found of Ubuntu Football Academy, in Cape Town, South Africa, days before he left for North Sentinel Island hoping to convert the Sentinelese to Christianity.

Photograph by Sarah Prince, AP

The director of a National Geographic documentary about the Andamans was wounded by a spear flung at him as he filmed the Sentinelese from a boat in 1974. Even today, the iconic images of warriors prancing with bows and arrows along the island’s white-sand beaches taken on that expedition by National Geographic photographer Raghubir Singh remain a testament to tribe’s defiance of the outside world.

That fierce reputation was reinforced in 2006, when two fishermen were killed by the tribe after their craft drifted ashore while they slept. Efforts to recover the bodies were abandoned after archers launched projectiles at a helicopter as it attempted to land.

Chau’s own death was made especially poignant by notes he scrawled in a journal after his first attempt to come ashore, on November 15. That initial approach was rebuffed when an arrow pierced a waterproof copy of the Bible Chau held aloft in his quest to evangelize the tribe. As he saw two other tribesmen readying arrows in their bows, Chau beat a hasty retreat in his kayak. He paddled back to the fishermen whom he’d paid about $350 to bring him there and await his return.

“Satan’s Last Stronghold”?

In his journal, Chau wondered if North Sentinel Island might be “Satan’s last stronghold,” and he expressed frustration that he hadn’t been greeted with open arms. “What makes them become this defensive and hostile?” he wrote.

Setting his fears aside, he resolved to go back that night. He instructed the fishermen not to wait for him this time and to deliver his notes to a friend back in Port Blair, the administrative capital of the Andaman Islands.

On November 17, the fishermen skirted the shore. From the distance, they later reported under police questioning, they saw the Sentinelese dragging a body and burying it on the beach. From the clothing and the body’s silhouette, they deduced that it was Chau.

India has charged seven people—including the fishermen and a local engineer and missionary identified as “Alexander” who allegedly helped Chau plan his trip—with “culpable homicide” and violating laws that strictly proscribe visits to the island.

“He knew he was very likely to get killed,” said Madhusree Mukerjee, a senior editor at Scientific American from Kolkata and author of The Land of Naked People, a book about her experiences among the indigenous peoples of the Andaman Islands. “He wanted to be a Christian martyr, and he is. What he probably didn’t realize was that this event would set in motion a series of developments would lead to actually harming the tribe.”

Fearing that international pressure could result in an attempt to recover Chau’s body, with unforeseen and possibly devastating consequences, she added: “This is an inflection point in the history of the Sentinelese.”

In the aftermath of Chau’s disappearance, authorities mounted three exploratory trips—one by air and two by boat—taking a pair of the fishermen with them to scout for the location of the body. On the second boat excursion, police saw five or six tribesmen with bows and arrows keeping watch along the beach.

“As of now, we don’t have any plan to confront them or land there, which would certainly create a lot of distress among them,” Andaman police director general Dependra Pathak told National Geographic by phone from his home in Port Blair. By law, Pathak said, not even the police are allowed to enter a five-mile buffer zone around the island. Still, Pathak said he was consulting anthropologists and even psychologists to better understand the possible impacts of the incident on the islanders, who might themselves be experiencing trauma. While he expressed strong reservations about attempting to retrieve the body, he did not expressly rule that out.

Both Pathak and the U.S. State Department acknowledge they’re in close consultation over how to proceed. Sources in Port Blair report that consular officials are seeking the return of Chau’s belongings, including his journal, and the issuing of a death certificate. Normally, a death certificate in India can’t be issued without a body to identify. “In an ideal case, yes,” Pathak said, acknowledging his country’s standard practice. “But here we will have to consider the reality.”

View Images Believed to number no more than a few hundred, the Sentinelese are deft archers and the only inhabitants of thickly forested North Sentinel Island. This photograph was first published in the July 1975 issue of National Geographic. Photograph by Raghubir Singh, Nat Geo Image Collection

Parallels with the Amazon

There was a time in the 1960s, 70s, and 80s, when Indian authorities actively sought to “pacify” the aboriginal tribes of the Andamans, including the Sentinelese. So-called “gift-dropping” expeditions cruised close to the shore, with team members heaving out coconuts, bananas, and plastic toys for the natives to retrieve. A breakthrough seemed to come on one trip in 1991, when several dozen Sentinelese came down to the beach unarmed, greeting the interlopers in waist-deep water to receive the gifts.

The efforts were similar in concept to expeditions undertaken through most of the 20th century half a world away in the Amazon. There too, Brazilian scouts—as well as American missionaries—used the lure of industrial goods and cultivated crops to woo uncontacted hunter-gatherers from the jungle.

“In the past, missionaries were a major force in contacting, pacifying, and settling isolated indigenous people throughout the Amazon, often causing demographic decimation and cultural erosion along the way,” said Glenn Shepard, an American anthropologist and ethnobotanist at Museu Paraense Emilio Goeldi, in Belém, Brazil.

And like the pacified tribes of South America, indigenous peoples of the Andamans soon succumbed to contagious diseases and wholesale social disintegration in the wake of contact. The Jarawa tribe, after laying down their bows and arrows on South Andaman Island in the late 1990s, has endured two deadly outbreaks of measles.

Their once proud warriors have been reduced to listlessness and alcoholism, their children even made to dance for handouts by unscrupulous tour operators guiding “human safaris” along the trunk road that now cuts through their traditional territory. Other Andaman tribes in turn have suffered demographic shock and cultural collapse following efforts to force them into settled communities.

Mindful of such failures and of lessons emerging from Brazil and other Amazonian countries that have steered a new course away from forcing contact on isolated tribes, Indian authorities abandoned their gift-giving overtures to the Sentinelese after the 1991 expedition.

The death of Chau has raised fresh concerns about the fate of the Sentinelese. In an open letter released to the media on November 26, a group of prominent Indian anthropologists and activists urged the government to definitively call off any efforts to retrieve the missionary’s body. “The rights and desires of the Sentinelese need to be respected,” the letter reads. “Nothing is to be achieved by escalating the conflict and tension, and worse, by creating a situation where more harm is caused.”

View Images Warriors prancing with bows and arrows along the island's beaches are a testament to the tribe's defiance of the outside world. This photograph was first published in the July 1975 issue of National Geographic. Photograph by Raghubir Singh, Nat Geo Image Collection

The unique situation of the Sentinelese—as the only uncontacted tribe in the world inhabiting their own island—makes them “exceptionally vulnerable” to diseases carried by outsiders, said Sophie Grig, an expert in Andaman tribes with the London-based indigenous rights group Survival International. “That’s a key reason we must respect their right to remain uncontacted,” she said. “Even without that, they’ve made it very clear that’s what they want.”

The Sentinelese must be keenly aware of the alien world that surrounds them. Aircraft cross their skies. Oceangoing vessels regularly darken the horizon. Their sharp arrow points are made of metal believed to have been scavenged from shipwrecks. They’re occasionally subjected to the prying lenses of tourists who, as Chau did, pay fishermen to evade coast guard patrols to approach the island.

Grig hopes the Indian government will redouble efforts to protect North Sentinel Island—and the Sentinelese. “It’s really important that those patrols are stepped up and the waters around them are properly policed and protected from any outsiders—fishermen, tourists or evangelicals.”

No one besides the Sentinelese themselves can know exactly why the tribe bears such hostility toward the outside world. Perhaps it dates back to a visit from British colonizers in the 1880s, when several of the islanders were abducted and later perished in British custody. Perhaps they instinctively sense that outsiders pose a clear and present danger—even those who approach with the best of intentions.