WASHINGTON, D.C.—Environmental advocates suspected it was coming, but few thought it would happen this quickly.

On Tuesday, President Donald Trump ordered the re-authorization and rapid completion of the Dakota Access and the Keystone XL pipelines, two controversial infrastructure projects that will make it easier to transport fossil fuels across North America. The move tries to fulfill a “Day One” promise of Trump’s to weaken the regulatory procedures blocking the pipelines.

“The regulatory processes in this country have become a tangled-up mess, and very unfair,” he said as he signed the order. In a less Trumpian register, the document itself says, “I believe that construction and operation of lawfully permitted pipeline infrastructure serve the national interest.”

It is Trump’s first major attempt to dismantle former President Obama’s environmental and climate record. Whether it will be a successful attempt is another story. Obama’s climate actions were mostly premised on the power of the executive, so they may be easy for a different executive to undo. But lawyers warn that the fights to come could mire Trump in years-long court battles over regulatory law.

Tuesday’s events fit an emerging pattern for the Trump administration. In the mid-morning, the White House announced that the president had signed orders reviving the two controversial pipeline projects. But it did not actually release the orders themselves until the mid-afternoon—which left lawyers and reporters alike scrambling to parse the text of the new laws from an Associated Press photo. This also meant that the national press reported the news for hours without knowing, exactly, what it entailed. Finally, by dusk, hundreds of people assembled outside the White House to protest the orders.

“There is a man sitting in that house right now who is not going to stand for anyone other than himself,” Eryn Wise, a member of the Jicarilla Apache Nation and an organizer for Honor the Earth, told the crowd. “There is a man sitting in that house who has laughed in the face of women, who has laughed in the face of Muslim Americans, who has laughed in the face of immigrants, who has laughed in the face of indigenous people.”

The protesters chanted: “We are not going away! Welcome to your fourth day!” The cheer echoed off the U.S. Treasury Building.

It is indeed interesting that, on his fourth day, the new president would choose to move forward on the Keystone XL and Dakota Access pipelines. According to the Dallas Morning News, Trump may own as much as a $1 million stake in the parent company of Dakota Access, Energy Transfer Partners, and its CEO also donated more than $165,000 to his campaign. (Trump has said he sold all his stocks in June 2016, but he has offered no proof of this.)

It is interesting for other reasons, too. In many ways, the two pipelines can be seen as mirror images of each other.

President Trump, surrounded by staff, addresses reporters after signing an order expediting the Dakota Access pipeline. (Evan Vucci / AP)

At this point, the Keystone XL exists more as an idea than as steel-and-nails infrastructure. Almost a decade ago, the TransCanada Corporation proposed Keystone XL as a 1,200-mile pipeline connecting the oil fields of Alberta to the refineries of Nebraska, and the company began the approval process for the international project.

In 2011, climate activists picked up on Keystone XL. Bill McKibben, a prominent activist and journalist, announced that approval of the pipeline would be “game over” for the planet, as it would open up previously inaccessible oil in the Alberta tar sands for burning. He and other activists successfully turned the idea of Keystone into a rallying point for the larger cause of fighting climate change. What was at stake, they insisted, was not the fact of the pipeline itself, but the continued commitment of U.S. dollars to fossil-fuel infrastructure.

It worked. People rallied against Keystone, insisting on its significance as a symbol even if they admitted its emissions might be insignificant. They discovered, too, that the Democratic Party had a political lever over the project: Because the Keystone would be an international pipeline, it required approval from the U.S. State Department—and, thus, from the Obama administration.

A newfound army of climate activists demanded that Obama reject the pipeline and finally take climate change seriously. In November 2015, the president did. The State Department announced that, as Keystone would not lower oil prices or create jobs, it did not believe the pipeline was in “the national interest.” Keystone XL was dead. Until Tuesday.

“The story of the Keystone XL pipeline is the story of how we built the grassroots climate movement in this country,” said Joelle Novey, the director of Interfaith Power and Light, a religious advocacy group that supports climate action. Novey showed up to the White House protest on Tuesday night; she said it was only the most recent of countless protests she attended against Keystone. “It’s a symbol,” she told me, “which is probably partly why Trump went for it on his fourth day.”

But even after the orders, it remains just that—a symbol with no substance. Since Keystone languished in federal review for years, almost none of it is built.

The Dakota Access Pipeline, on the other hand, is more than 80 percent complete. It is contained entirely in the United States, connecting the oil fields  of North Dakota to a river-port refinery in Illinois. And it is constructed almost entirely on private land leased by Energy Transfer Partners.

In fact, the entire pipeline only needed one major federal permit: permission to construct beneath Lake Oahe, a reservoir constructed by the Army Corps of Engineers in the early 1960s and controlled by them ever since. Lake Oahe is directly upstream of Standing Rock Sioux reservation; it is also the tribe’s only source of drinking water. The tribe complained that the pipeline had been sprung on them, and that the pipeline never received a site-specific environmental review. Many members of the Sioux feared that if the pipeline leaked and poisoned their water, there would be nothing they could do about it.

Throughout 2016, the Standing Rock Sioux and Native people across the continent—aided in part by the climate movement, which has experience opposing pipelines—succeeded in building nationwide recognition of the Dakota Access Pipeline. Through protests and spectacle, they turned the tribe’s legal struggle into a national news story. And in early December, the U.S. Army Corps of Engineers announced that it would undertake a full environmental review for the pipeline, a process that could take two years.

The move was chalked up to the Obama White House, though legal experts told me that President Obama himself could not easily have made the directive. At the time, Energy Transfer Partners attacked the president, saying he had “abandoned the rule of law in favor of currying favor with a narrow and extreme political constituency.”

The company added that it expected to “complete construction of the pipeline without any additional rerouting in and around Lake Oahe. Nothing this administration has done today changes that in any way.”

Now it may have its chance. President Trump’s directive to revive the pipelines took the form of four different presidential memos or orders on Tuesday. In the first, Trump invited TransCanada to resubmit the Keystone XL pipeline proposal to the State Department. He also gave that department a 60-day deadline to approve or decline the project.

In the second, he asked the U.S. Army Corps of Engineers to “review and approve in an expedited manner” the Dakota Access pipeline. He also asked the Corps’s director to “consider, to the extent permitted by law and as warranted, whether to rescind or modify the memorandum” from December that granted a new environmental-impact statement for Lake Oahe.

His other two memos were less interesting. One asked the Secretary of Commerce to figure out how to require materials for American pipelines be made in the United States. It’s unclear whether Trump can order that private businesses comply with this plan or whether this order just duplicates the Buy American Act of 1933, which requires the federal government and some of its contractors to purchase American-made products. The last memo ordered all executive agencies to speed up environmental reviews for “high-priority infrastructure projects” as quickly as the law permits. This resembles orders issued by other Republican presidents, including George W. Bush in 2001.

But it’s those two pipeline-specific memos that have made headlines. Will they succeed in nudging Keystone XL and Dakota Access toward completion?

Legal experts say it’s unclear. And it’s likely that, in the near term, there will be lawsuits about these documents.

“It’s the flip-side of the question everyone was asking last year, ‘Why doesn’t Obama just put the kibosh on Dakota Access?’” said Sarah Krakoff, a professor of tribal and resources law at the University of Colorado Boulder. “Well, it’s not really his role. It’s the Army Corps’s role, and that’s still true today.”

“Trump can’t, with the stroke of a pen, just make the Dakota Access pipeline happen. He just can’t. He doesn’t have that authority. It’s his agency’s authority, and he can’t revoke the laws that the agency just found that it has to comply with,” she added.

She added too that the executive orders seemed to be written in a typical way. Instead of commanding agencies to ignore congressionally passed law, the orders request that they expedite or reconsider previous judgments. “Executive orders are legal orders—they’re law—but they can’t contravene legislative enactments. So an executive order can’t say, ‘Ignore the [National Environmental Policy Act] and give me a pipeline,’” she told me.

“If the federal law gives decision-making authority to a particular official, that official has to make the decision,” said John Leshy, a professor of real property law and a former general counsel to the U.S. Department of the Interior. “But there’s some murkiness about what the president can do. The decision maker can say no, and then the president can fire them and replace them with someone who would. But that takes time.”

Krakoff added that it would attract judicial suspicion if the Army Corps of Engineers suddenly decided that it didn’t have to make an environmental-impact statement for the Dakota Access pipeline after saying that it did just weeks ago.

“It would be hard for them to turn around on a dime and say, ‘We got this piece of paper from the president and now we don’t think that’s necessary,’” she said. “If the agency were to take a different route, legally, now, I would strongly suspect that that would be subject to litigation.”

Earthjustice, the environmental-law nonprofit leading the Dakota Access suit, said that they are studying the orders and waiting to see how the Army Corps reacts.

Experts seemed to think the Keystone XL pipeline would be easier to restart, at least from a legal perspective. The obstacles to that pipeline originated in the federal government and not an ongoing legal challenge. But in a way, that highlights the paradox of the two pipelines: While it may be easier to restart Keystone XL legally, none of that project is built, and there’s no guarantee that it ever will be. The Dakota Access pipeline, meanwhile, sits idle at 80-percent completion. It is closer to being done. It also has, legally, much further to go.

Dakota Access seems also to have captured an aspect of the public progressive imagination that Keystone XL never did. Most of the protesters I saw on Tuesday carried signs about that pipeline. They chanted Mni Wiconi,’ which means “water is life” in Lakota. Dakota Access has engaged the parts of the left concerned about the environment and concerned about social or racial justice. And not only will blocking the pipeline help the climate (at least a little bit), it will also protect the water supply of a long-oppressed and abused community.

“We both feel very strongly about Dakota Access,” said Basmah Rahman, a young public-health employee who walked to the White House protest with her friend after they got out of work. “It’s about making sure that Native people who live there are respected, and their sacred land is respected.”

Tuesday was one of the first protests Rahman had attended while living in D.C. While we talked, she frowned at the White House. “His first week has made a strong statement—he’s not listening to anyone who doesn’t already support him. And that’s not the way it’s supposed to be. He’s supposed to be the president of everyone,” she told me.

Right now, he indeed seems to be reveling in the power of that office. Soon he may discover its limits. On January 22 of a different inauguration year, 2009, another revolutionary and change-making president made good on a campaign promise. In an executive order signed in front of a similarly large press junket, Barack Obama promised that the Guatanamo Bay detention center would close within a year. Human-rights advocates around the world praised the decision.

But on January 22, 2010, the facility was still open. And on January 22, 2013, two days after that president’s second inauguration, it remained open as well. And on January 22, 2017—two days after he left the presidency—the infamous facility still imprisons 41 men.

An executive order may make headlines today. Whether it shapes reality is a different question.