The scenes at the protests at Standing Rock over the Dakota Access pipeline in the past year have been extreme, at times terrifying: guards unleashing dogs on peaceful demonstrators, police spraying freezing cold water on the protesters, and journalists arrested while doing their jobs.

Yet behind all this drama, it became easy to miss that this battle is intrinsically linked to Supreme Court cases from nearly 200 years ago. But for Native Americans taking a stand for their tribal lands, that’s exactly what the pipeline battle is largely about.

The protests are rooted in a concept that was cemented in US legal doctrine by a trio of Supreme Court cases from the 1820s and ’30s: tribal sovereignty. This is a legal idea that Native American tribes aren’t formally part of the states they reside in, but rather semi-autonomous nations with rights to self-governance that stop states and, in some cases, even the federal government from interfering with tribal issues.

This is at the heart of the debate over the Standing Rock protests. While many people have rallied around the local Standing Rock Sioux for many different reasons (such as worries about what the pipeline could do to the environment and a general opposition to corporate greed), tribal sovereignty has been the primary focus of Native Americans from the area. Essentially, they argue that their sovereign rights have been violated by a federal government that allowed private companies to build a potentially dangerous pipeline through waterways that are crucial to their lives.

That battle rages on. And in a significant setback for opponents of the Dakota Access pipeline last week, a judge refused to stop the construction of the pipeline after the Sioux sued, arguing that the pipeline would hinder their religious practices — and oil could begin flowing through the pipeline as early as this week. That, legal experts say, would be yet another example of the federal government violating their rights.

There’s a historical case here: Tribal sovereignty has never been fully respected by the US, which often encroached on and abused tribes under federal rule. Today’s Dakota Access pipeline battle, then, is emblematic of the general mistreatment that Native Americans have faced over the centuries after a few strange white men landed on the eastern shores of the Americas.

A simple way to think about tribal sovereignty

“The way to think about tribal sovereignty is tribes have powers that are very much like the powers of one of the 50 US states,” Joe Kalt, an expert on Native American issues at Harvard University, told me. “We’re used to multiple levels of government in the United States with our states. And tribes’ powers parallel well with our states.”

So just like states, tribes have their own constitutions, their own elections, their own police, their own tax systems, and their own legislatures. The one big difference, Kalt said, is that tribes get their powers from inherent sovereignty — as the first sovereign nations on the continent — along with the US Constitution, treaties, and court cases. States, on the other hand, mostly get their powers from the US Constitution’s explicit protections for federalism.

This is why, for example, tribes can legalize casinos even if they reside within the borders of states that ban them. “California can’t tell Nevada whether Nevada can have casinos. And Nevada can’t tell Utah,” Kalt said. Similarly, tribes have the jurisdiction to decide if they want casinos within their borders.

That doesn’t mean that the US doesn’t have any say over what goes on in tribes. Just like states, the federal government does have the capacity — in some specific cases, even greater capacity than it does with states — to regulate activity within the tribe. But there are limits.

“Certain aspects of federal law recognize tribal interests, even beyond tribal boundaries,” Kalt explained. “So many tribes will have historic and heritage sacred sites off reservations. But they will have certain rights.” For example, the Native American Graves Protection and Repatriation Act (NAGPRA) allows tribes to reach out to federal agencies and other federally funded entities to demand and reclaim Native American “cultural items” that have fallen out of the tribe’s possession.

Much of this goes back to a series of Supreme Court cases in the early 19th century: Johnson v. M’Intosh, Cherokee Nation v. Georgia, and Worcester v. Georgia. The specifics of each case varied. But generally, Chief Justice John Marshall “set out this idea that tribes are diminished sovereigns,” Robert Williams, faculty chair of the Indigenous Peoples Law and Policy Program at the University of Arizona, told me.

Essentially, that meant tribes had the right to self-govern, but they weren’t able to deal with foreign nations — by, for instance, selling their lands or making treaties — since that was left to the federal government. That concept of tribes as a diminished sovereign has broadly stuck since the trio of Marshall rulings, Williams said.

The Dakota Access pipeline protests are largely about tribal sovereignty

When it comes to the Standing Rock Sioux and the Dakota Access pipeline, there are two big tribal sovereignty issues: The Sioux are worried that their waterways will be polluted if the pipeline were to leak, and that their sacred land will be irredeemably damaged through the construction and maintenance of the pipeline.

Consider how states would deal with the waterways issue: Let’s say Arizona wants to build a pipeline that could, in the case of a leak, potentially affect a river that flows into California. In such a case, California would want some assurances in place that its own public safety concerns are being considered. And Californians would likely be very angry if their own interests weren’t part of the process. They may even argue that it’s a violation of the state’s sovereignty for Arizona to endanger its waterways.

This is essentially how the Sioux currently feel about the entire process. Technically, the pipeline isn’t on tribal grounds, but its existence could still affect the tribe — and allowing those effects to go on without closely consulting the Sioux would be a violation, in the Sioux’s view, of their tribal sovereignty.

“The problem with water is it’s moving,” Williams said. “When the Sioux say they have sovereign rights to water, it’s the water when it reaches the reservation. But if it’s polluted before it reaches the reservation, then their sovereign rights have been invaded.”

This is further complicated by the fact that part of the pipeline goes over what the Sioux consider sacred land that’s off their reservation. Tribes are supposed to have some ability to visit and keep these sites for ceremonies under their sovereign rights.

Yet so far, the federal government hasn’t been receptive to these concerns, instead letting the pipeline move forward. The Army Corps of Engineers, in strictly following only its legal obligations, focused its permit assessment just on environmental impact, not tribal sovereignty.

“At the minimum, the construction of a pipeline would require the US to consult with the Sioux fully in a way much more thorough and much more focused than the Army Corps of Engineers has done so far,” Williams argued. “In that, the pipeline has larger social, economic, and environmental impacts beyond the narrow geographic area that the Army Corps issued its permit for.”

The corps has argued that it adhered to the strict legal requirements, and repeatedly tried to reach out to the Sioux, sometimes getting no responses.

But the corps also acknowledged that it withheld key documents, particularly studies evaluating the pipeline’s risks, during its consultations with the Sioux — which suggests that the Sioux had reason to be suspicious in their talks with the corps. That suspicion is further validated by America’s long history of mistreating tribes.

The US has a long history of flouting tribal sovereignty to abuse Native Americans

The example of the Dakota Access pipeline reflects a broader problem in America: It is true that, in theory, tribal sovereignty is a well-established legal concept that the US is supposed to respect. But in practice, that has often not been the case.

There are the big examples, exemplified by the various waves of abuse against Native Americans throughout US history followed by attempts at reconciliation. Generally, this tug and pull left the Native Americans worse off than they were before — even if they ultimately did end up with some protections after centuries of mistreatment.

Perhaps the most well-known of these travesties is the Trail of Tears. In 1830, President Andrew Jackson signed the Indian Removal Act into law. The measure was supposed to allow negotiations with tribes to move them off tribal lands, which the US wanted for its own uses. But it was instead used by Jackson and other government officials to coerce and force Native Americans to leave their homes — without the proper help to overcome the weather, disease, and other horrors that would plague them on their journey. The actual death toll is uncertain, but for the Cherokees alone, it’s estimated that 4,000 to 8,000 died as a result of the forced removal.

Then there was a period later in the 19th century in which the federal government tried to forcefully assimilate Native Americans. The National Congress of American Indians explained:

Settlers' increasing desire for the land within reservations and the push to assimilate Indians into mainstream American life led to the General Allotment Act of 1887. This Act (also known as the Dawes Act) dictated the forced conversion of communally held tribal lands into small parcels for individual Indian ownership. More than 90 million acres — nearly two-thirds of reservation land — were taken from tribes and given to settlers, most often without compensation to the tribes.

This approach would eventually be pulled back in 1934, as the federal government tried to reach out to tribal lands to help them reform their governments and build more sustainable economies. Then Congress began to pull back the more inclusive approach in 1945, as it stopped recognizing more than 100 tribes and imposed state policies on them. Finally, later in the 20th century, the federal government eventually moved in a friendlier direction again — taking steps to respect tribal sovereignty.

Overall, Native Americans lost a lot in this back and forth, visualized by this animated map:

There are also examples of smaller violations of tribal sovereignty, some of which seem particularly relevant to the Dakota Access pipeline protests. In the 1940s, the federal government went through with the Pick-Sloan Missouri Basin Plan, building a dam on Lake Oahe, the site of much of the Dakota Access pipeline protests today. The dam led to flooding in the area, destroying tribal lands for farming and hunting and displacing hundreds of families, according to the National Park Service.

Many of these abuses can only be explained by racism and disrespect for human or tribal rights. It is simply impossible to reconcile something like the Trail of Tears with a basic sense of human decency. And federal projects like the Pick-Sloan Missouri Basin Plan were carried out with little regard to the potential impact on Native Americans.

But some of the problems are rooted in cultural differences about how treaties were used. Many tribes didn’t imagine that they couldn’t, for example, continue to hunt, visit burial grounds, or hold ceremonies in sacred grounds in non-tribal lands. Yet very often, that’s how US officials interpreted the treaties.

“You were dealing with different cultural constructs of what a treaty meant,” Williams said. “In Sioux treaty traditions, the purpose of the treaty was to bring people together, to incorporate them into your clan and tribal structure. And the purpose of a treaty when white people made it was to draw lines — Protestants on this side, Catholics on the other; Spanish on this side, Portuguese on the other.”

The US and other foreign powers were able to abuse this misunderstanding repeatedly throughout history, using treaties that many tribes didn’t totally understand to coerce indigenous populations into leaving their lands.

Looking back at this history, it becomes a lot easier to understand why the Sioux were so skeptical of their interactions with the Army Corps of Engineers and so steadfast in their protests: After centuries of abuse, they couldn’t expect much good to come out of their interactions with the federal government.