When it comes to Trump’s proposal to build a wall between the U.S. and Mexico (never mind the fact that many such physical barriers already exist), many people have focused on two questions: Shouldn’t there be comprehensive immigration reform instead? And who’s going to pay for it?

But there’s another question we should ask. Who is going to build it?

I’m referring to the engineering companies that will actually design and construct “the wall.” Whatever form it takes (a monolith or a mishmash), hundreds of companies are lining up to build it—and that reflects the willingness of many companies to profit from divisive politics. Unfortunately, engineering education, practice, and ethical codes provide engineers almost no guidance on the broad political implications of their work.

The presidential administration has only just begun the lengthy process of building the wall. First, on Feb. 24, the Customs and Border Protection office issued a pre-solicitation to gauge interest from companies. (The response was overwhelming, with more than 600 companies submitting proposals, of which, according to a CNBC analysis, “[a]t least 133 companies were listed as owned by minorities—including 39 by Hispanics.”) Then, on March 17, CBP issued two detailed solicitations—one for designing and building a concrete wall and another using other structures. These solicitations will really set in motion the engineering process.

Before any concrete is poured, within companies, there will be spirited discussion and debate among engineers and managers about design and costs. Memos will be written, and company leaders will be briefed. The administrative work of contracting will take shape. If a company doesn’t have the expertise or skills to do a particular task, it may join forces with another company or group of engineers who do. In short, the wall will be a product of engineering decision-making.

But how much of the decision-making process will discuss the ethics of being involved with building a wall between the U.S. and Mexico?

When big contracts are on the table, there can be very little incentive for a company to refrain from doing the work in the name of good moral behavior or the public welfare. For instance, leading engineering companies are involved in designing and building pipelines to bring more tar sands oil from Canada to the U.S., in spite of the negative social and ecological impacts.

Social justice advocates see the wall within a broader discussion about immigration, and engineers should, too. Engineers have a moral responsibility to understand the context of their work. The federal judge who recently blocked the Trump administration’s second immigration-related executive order put it in the context of language used by the president over the past several months. Similarly, engineers cannot and should not view the wall as a singular engineering project. Instead, they should think of the social and political implications of the barriers that already exist between the U.S. and Mexico, and they should evaluate the social, political, and humanitarian implications in the context of another wall born of divisive politics—the one between Israel and the Palestinian territories of Gaza and the West Bank. Among a host of humanitarian and human rights issues, the wall between Israel and the Palestinian territories has created incredible animosity. The wall has become a symbol of conflict for so long that both Israeli and Palestinian children “grow up feeling that they are destined for conflict with their neighbors,” according to Laurel Holliday, author of Children of Israel, Children of Palestine. But for companies bidding on the U.S.-Mexico wall, the politics of the project have been stripped away and translated into technical specifications.

In today’s political climate, engineers cannot remain passive and allow legislators and politicians to decide what the “public good” is. All members of a community must be engaged and responsible in deciding what the public good is and how to create it—and that goes especially for engineers and the companies they work for, because they can have a disproportionate and lasting impact on a community.

But the engineering community’s response thus far has been divorced from these important issues. Here’s what representatives of three bidding companies have said:

“We’re not into politics. We’re not left or right. We’re a construction company and that’s how we survive. … We don’t see it as politics. We just see it as work,” Jorge Diaz, who manages De la Fuente Construction Inc. in California, told the Guardian.

“We’re focused on the work, we’re not a political body, left or right or what have you. We go after the job and provide high-paying jobs for our workforce and great opportunities for our company,” Ralph Hicks, vice president of governmental affairs for R.E. Staite Engineering in California, said to KPBS.

“There could be a political backlash, but we are in business to make money and put people to work and provide a good service, whether it’s a wall or substation or airport or prison. We don’t want to approach it from a political standpoint, only from a business standpoint,” George Ishee, national sales manager for Cast Lighting, based in Hawthorne, New Jersey, told a local newspaper.

Another engineering company owner, Patrick Balcazar, who owns San Diego Project Management in Puerto Rico, went even further, suggesting that building a wall will provide a future economic opportunity to employ engineers to tear it down: “My goal is to build a wall so I can make enough money so we can turn this thing around and tear down the wall again.”

Not every company bidding for the wall will share these points of view, but they highlight a particular problem with how many engineers and companies see their role in the world and how their work is valued. As it stands, much of engineering is focused more on financial incentives than social impact and human welfare.

Further, the reality is that engineers and companies always work with or for someone with particular political motives, and so their work is always political. By saying building a wall is “just work,” engineers and companies shift the moral burden from themselves—those who actually design and build these projects—to those who order and pay for them. But people, politicians, and governments can talk all they want about doing something; they do not have the skills to actually do it.

The fundamental canon of the Code of Ethics by the National Society of Professional Engineers states, “Engineers, in the fulfillment of their professional duties, shall hold paramount the safety, health, and welfare of the public.” Unfortunately, there is only vague guidance given to engineers on how to implement this canon, with emphasis more on client relationships rather than social good. The American Society of Civil Engineers Code of Ethics does a better job here. It says: “Engineers shall recognize that the lives, safety, health and welfare of the general public are dependent upon engineering judgments, decisions and practices incorporated into structures, machines, products, processes and devices,” thus pointing to the political implications of engineering work.

For engineers working on politically charged projects, there can be friction between their professional obligations and their moral obligations, dilemmas they are untrained to grapple with. While an engineer may raise concerns about the safety of a project (to make sure, for example, the wall won’t collapse and hurt a border patrol officer), there tends to be little to no support for engineers who question the morality of the project they work on.

But just because a project is politically and professionally justified and economically feasible does not make it ethically or morally justified. That’s why it’s frustrating that most engineering education programs across the country provide only scant ethical training, particularly in the context of social good; there are few resources, examples, and role models for ethically conflicted engineers to turn to. Engineers have incredible power, but if they aren’t managers or company leaders, it can be difficult to speak up about the ethics of particular projects. Historically, engineers have been routinely ostracized and silenced when questioning leadership decisions. For example, engineers predicted the failure of the O-rings on the Challenger space shuttle’s solid rocket boosters yet NASA proceeded with launch. We all know what happened next.

Look through most engineering programs at colleges and universities in the U.S. and you’ll see very few courses dedicated to ethical training. Frequently, those that are offered aren’t required, or ethics forms a two- or three-week component of other classes, either at the beginning or the tail end of an undergraduate career. Efforts to infuse ethical training deeply in engineering education struggle against already packed course schedules, and ethical issues are rarely discussed at engineering conferences. So those of us who are engineers have to take it upon ourselves to deeply engage with the ethical challenges and dilemmas we face. Engineers should constantly ask themselves (adapted from the founding document of Science for the People): Why are we engineers? Who do we work for? What is the full measure of our moral and social responsibility?

If engineering is only about making money, then let’s not call it engineering; profiteering would be a more appropriate description. But if engineering is “rooted in a goal to improve our societies by producing structures that render them more just, more equitable, and more beautiful,” as the Architecture Lobby writes, we—engineers—need to do a better job at thinking about who and what is affected by the choices we make. If engineering is about working on technical projects that “hold paramount the safety, health, and welfare of the public,” then a thoughtful, compassionate, and contextual reading of this fundamental canon cannot justify engineers giving their expertise, time, and resources to a border wall that will embolden and embody divisive politics.

“We’re just doing our job” just does not cut it with morally challenging, hot-button issues. It never has, and it never should.

This article is part of Future Tense, a collaboration among Arizona State University, New America, and Slate. Future Tense explores the ways emerging technologies affect society, policy, and culture. To read more, follow us on Twitter and sign up for our weekly newsletter.