Germany has had experience with walls - but the memories aren't happy. That could be why, despite a wealth of multinational construction firms (an industry that represents some 10 percent of Germany's GDP), only two German companies are listed among the 700 said to be interested in building Donald Trump's proposed wall along the Mexican-US border.

Both of these companies have now distanced themselves from the US president's flagship anti-immigration project, clarifying that they had registered so as to be updated on the competition, not because they wanted to take part.

The Bavaria-based Bauer AG, which boasts 110 subsidiaries and nearly 11,000 employees working in around 70 countries, reacted with some consternation to a report in Thursday's "Süddeutsche Zeitung" daily that noted its presence on the list.

"The fact is, it is normal in the US to enter yourself on the information mailing list for competitions - which 700 firms did in this case, and which is standard practice," spokesman Christopher Wolf told DW by email. "There are no efforts from Bauer's side to participate in this project!"

But Wolf was not content to leave it at a simple clarification of the company's intentions. "Beyond this, Bauer completely rejects the rhetoric and moral position of US President Trump on the subject of building walls," he added.

Bringing people together

The other company on the list was Leupold Brown Goldbach, a Munich architect's studio with an office outside Boston, Massachusetts. It too was mentioned in the "Süddeutsche Zeitung," and was concerned that its intentions hadn't been clear in the report.

"We didn't do this because we want to be part of a big job in America - quite the contrary," partner Andreas Leupold told DW. "We wanted to be part of the protest movement against this project."

Leupold said he sees his company as part of the "Alt-Wall" movement - a collective of artists, intellectuals and architects specifically set up to voice its opposition to Trump's colossal construction project. "There are definitely better solutions," said Leupold. "And we felt compelled to contribute to that opposition in some way."

Leupold is also worried that his profession has been "much too quiet" about Trump's wall. "This is an architectural task - it's a monumental construction project that is supposed to be built there, and architects haven't really said anything about it," he said. "That's why we thought [Alt-Wall] would be a good platform to announce that, and so inspire a wider discussion."

Germany's wall-phobia

It's certainly notable that not a single German company has signaled any intention to bid for the Mexican border wall. There was a flurry of media speculation at the end of February when Marcelino Fernandez Verdes, CEO of Hochtief, one of Germany's biggest multinational construction firms, did not rule out bidding for the project. But the company put out a statement within days clarifying that Hochtief had "no plans" to be part of the border wall.

"You definitely wouldn't get good press as a German company - in Germany, just the word 'wall' has a lot of power as a symbol," said Leupold. "That might well be why no one has taken part yet. For us as an architect's studio, we asked ourselves what we stand for - we always want to be for openness, transparency, for democracy - and not division."

The US Department of Homeland Security posted its request for proposals for a "Solid Concrete Border Wall" on March 17, saying it wants Trump's wall to be at least 18 feet (5.5 meters) tall, stretch the length of the 1,933-mile US-Mexican border, and be impervious to attempts to climb over or tunnel underneath it. Private contractors interested in a commission will be asked to build 10-foot prototype sections and then provide more details in May.