Deep in the Amazon rainforest, armed tribesmen battle illegal loggers for their future — and ours The "Guardians of the Forest" have taken up arms against the "invaders."

Know it or not, Laercio Guajajara is fighting for you.

The 35-year-old indigenous Brazilian is a member of the Amazon’s Guajajara tribe and the leader of what is essentially a paramilitary group who have made it their mission to expel illegal loggers from the rainforest that has supported their people for centuries.

Calling themselves the “Guardians of the Forest,” this small band of no more than 50 tribal fighters patrols roughly 1,600 square miles of federally protected land, disrupting and detaining the so-called “invaders” who cross their path.

But for Laercio and his “Guardians,” this is no mere local skirmish. The pace of deforestation in the Amazon has alarmed world leaders who fear it could exacerbate the effects of climate change, putting the Guajajara on the front lines of a fight with global implications.

“This land help[s] us indigenous to survive,” Laercio told ABC News. “At the same time it serves the whole world, all the people who live on this planet.”

Watch the full documentary “Guardians of the Amazon” on the streaming news channel ABC News Live Friday at 8 p.m. ET. A special version of the documentary will air on “Nightline” on Wednesday, Feb. 19 at 12:35 a.m. ET on ABC.

Last summer, ABC News was granted rare access to the “Guardians” and their operations, embedding within their ragtag convoy of trucks and motorcycles during a four-day patrol over several dozen miles of dense terrain.

With cameras rolling, the “Guardians” pursued an illegal logging operation deep into the jungle, employing satellite imagery, intelligence gathering and old-fashioned tracking along the way.

The portrait that emerged, which will be presented in documentary form on ABC News Live on Friday and broadcast as a special edition of "Nightline" on Tuesday, captured a complex struggle, featuring powerful industrial interests, complicit tribal villagers, indifferent government agencies — and an ever-present fear of violent reprisals.

Laercio, for his part, said he “never” leaves his house unarmed.

“I have to defend myself in every possible way,” Laercio told ABC News. “Because I don't want to die.”

Success for the group is often hard-fought and short-lived.

After two days of patrolling — often in the middle of the night in order to avoid detection — Laercio and the “Guardians” donned masks and surprised a small cadre of illegal loggers in the act of looting the tribe’s land for resources. Armed with guns, machetes, clubs, and even bows and arrows, they quickly captured seven men who appear to have been collecting lumber for eventual sale to local ranchers.

But it’s clear that these detainees are low-level players in the industry, a small part of a big problem. One of them, a younger man, told his captors that extreme poverty had made this type of work a necessity.

“I don’t have anything, nothing,” he said. “I am very poor. So I came here to try and make a living.”

The “Guardians” burned the lumber and drove seven hours to deliver their prisoners to the federal police headquarters in Imperatriz, where they were charged with illegally entering indigenous territory and released the following day.

Laercio expects the Guajajara will see them again.

“But I think it will remain the same, the justice will take them, but soon they will release them,” Laercio told ABC News. “Soon they will be in the forest destroying again, right? Because there will be no severe punishment for them.”

Watch the full documentary “Guardians of the Amazon” on the streaming news channel ABC News Live Friday at 8 p.m. ET. A special version of the documentary will air on “Nightline” on Wednesday, Feb. 19 at 12:35 a.m. ET on ABC.

The “Guardians” are also standing against some of the most powerful political and economic forces in the country.

According to the Guajajara, the devastation of their homeland has accelerated since the election of Brazil’s far-right president Jair Bolsonaro — known as the “Trump of the Tropics” — who has openly called for the development of the Amazon and has a history of disparaging the indigenous people who oppose it.

“The Indians do not speak our language,” Bolsonaro said in 2015. “They have no money. They are a sad people. They have to integrate into our society.”

Bolsonaro has faced widespread condemnation from the international community as slash-and-burn tactics to clear pastures for cattle ranching have led to rampant forest fires in the region. Scientists fear that the Amazon could be at a crucial tipping point, with its deforested areas emitting more carbon dioxide than they absorb, threatening its continued ability to mitigate global climate change.

But Bolsonaro’s office declined ABC News’ request for an interview with the president and directed questions about the issue to much-criticized environmental minister Ricardo Salles. Since taking office, Salles has slashed his own agency’s budget and reduced fines for businesses that commit environmental crimes.

In response to questions from ABC News, Salles offered a series of commitments from the federal government to indigenous people that appeared at odds with their reality in the rainforest.

“If it's the group decision,” Salles told ABC News, “they want to continue their way of life exactly as it is, and some sort of assurance that they need for the federal government, that's for sure.”

Laercio suggested that the federal government’s stance doesn’t match the reality in the rainforest.

“Bolsonaro needs to see this, to realize who are the real criminal[s],” Laercio told ABC News. “If he supports this kind of thing in the forest, he is the same as these guys here.”

Battles have casualties, and this one is no different.

According to Survival International, an international advocacy group for tribal people, more than 80 members of the Guajajara tribe have been killed defending their land over the last two decades.

Just a few weeks after ABC News left Brazil, Laercio and his friend and deputy Paulo Guajajara were ambushed, presumably by loggers, while they were hunting for food in the rainforest. Laercio was shot twice but managed to escape. Paulo, however, was killed.

Two suspects have been charged with “involuntary manslaughter” for his death, but legal experts say the men are unlikely to be prosecuted for what the government considers an “accidental” shooting.

Laercio does not expect justice for his friend, and though he is devastated by the loss, he believes the battle between the “Guardians” and the “invaders,” will continue for as long as there is a rainforest to defend.

“From what I've been observing for some time now,” Laercio said. “This represents the beginning of a war.”

Watch the full documentary “Guardians of the Amazon” on the streaming news channel ABC News Live Friday at 8 p.m. ET. A special version of the documentary will air on “Nightline” on Wednesday, Feb. 19 at 12:35 a.m. ET on ABC.

This report was featured in the Friday, February 14, 2020 episode of “Start Here,” ABC News’ daily news podcast.

"Start Here" offers a straightforward look at the day's top stories in 20 minutes. Listen for free every weekday on Apple Podcasts, Google Podcasts, Spotify, the ABC News app or wherever you get your podcasts.

ABC News’ Dylan Goetz and Allie Yang contributed to this report.