In the aftermath of Trump’s controversial Dakota Access Pipeline executive order, U.S. military veterans are returning to Standing Rock to (once again) put themselves between protesters and police. In December, roughly 1,000 veterans descended on Standing Rock to form a “human shield” between increasingly aggressive police and “water protector” protesters.

The protest against the Dakota Access Pipeline began as a wholly peaceful effort roughly one year ago. That’s when the first water protectors showed up, set up camp, and vowed to remain until the course of the controversial pipeline was diverted away from Lake Oahe. The protests against the pipeline began with the Standing Rock Sioux Tribe, who claim that the multi-billion dollar crude oil causeway will threaten their fresh, safe drinking water.

As the tribe took their battle against the pipeline to the courts, it began to garner more and more attention. After ultimately losing their legal fight over the summer, the Standing Rock protest found itself attracting more and more activists from across the nation. During the height of the presidential campaign season, candidate Jill Stein even joined in the melee, reportedly defacing construction equipment belonging to pipeline builders.

So proud of people standing up for Standing Rock @MikeHudema @likeagirlinc — Helen Turner (@43536H) February 11, 2017

Federal agents making arrests at the prarie knights casino & reports of EPA officials in the camps #VetStand #NoDAPL #Resist #StandingRock — Veterans Stand (@VeteransStand4) February 10, 2017

@VeteransStand4 this sounds really serious. I keep hearing Waco in my head. This is it. It's this day where we win or lose. Do something. — Jack A Roo (@JackARo710) February 10, 2017

By autumn, the Standing Rock protest camp had grown to well over 1,000. Police interactions became increasingly brutal, with “non-lethal” force being used against trespassing water protectors pushing onto land owned by Energy Transfer Partners, the entity behind the DAPL. Water protectors even found themselves dealing with vicious attack dogs, property of a private security company, and several Standing Rock protesters were injured in one incident. As the weather in North Dakota turned colder, water protectors at Standing Rock found themselves hosed down by law enforcement in sub-freezing weather.

As relations between Standing Rock protesters and law enforcement deteriorated and the harsh North Dakota winter loomed, the federal government and North Dakota governor issued dual orders announcing that water protectors were about to be evicted. In response, U.S. military veterans from across the country joined forces, raised funds, and traveled to Standing Rock from about December 4 to December 7. The mass eviction of Standing Rock protesters never happened, as the veterans formed human shields to protect the water protectors. Not to mention present a formidable visual deterrent.

Just days later, President Barack Obama intervened on behalf of the Standing Rock Sioux Tribe. Under his administration, the U.S. Army Corps of Engineers rescinded a vital easement that would allow pipeline construction to commence under Lake Oahe, advising contractors to find an alternate route. Despite hundreds of arrests, dozens of injuries (some severe), and months of increasingly volatile interactions with police and private security forces, Standing Rock water protectors (with the help of U.S. veterans) celebrated their victory.

Unfortunately, it was to be a short-lived celebration. Energy Transfer Partners vowed that the DAPL would be completed on its planned course. The Texas-based company waited for the new POTUS, Donald Trump, to be sworn in. Under his administration and by way of a controversial executive order, the completion of the pipeline was once again green-lighted. Once again, veterans began raising money to head to Standing Rock. Soon thereafter, protesters at the site were arrested en masse, prompting even more outrage and activism.

Led by a group called Veterans Stand, U.S. military veterans are making their way back to Standing Rock, near Cannon Ball, North Dakota. As The Guardian reports, the first round of brave former soldiers headed to Standing Rock to put themselves between water protectors and those in the government who would remove them from the site arrived on Friday.

According to the U.S. veterans who have headed back to Standing Rock (some who didn’t make it in December), they are there to protect the few hundred remaining, largely Native American, protesters from further “attacks by a militarized police force.”

A handful of veterans have already made it to Standing Rock. More are on their way, and hundreds if not thousands more are standing at the ready, waiting for the call to “deploy” to North Dakota in an effort to discourage the use of excessive force on remaining water protectors.