MUKRAN, Germany — The steel-and-concrete pipes measure 36 feet long, weigh 24 tons and, if a Russian-led consortium has its way, will stretch for nearly 800 miles along the bottom of the Baltic Sea.

Being churned out by the thousands at a waterside factory on this German island, the pipes offer evidence that Moscow will soon have a vital new means to sell its gas to continental Europe.

But what the $12 billion pipeline will ultimately deliver is a matter of fierce controversy — and could be the subject of sharp disagreement when President Trump and German Chancellor Angela Merkel meet in Washington on Friday. 

To its powerful backers, the mega-project known as Nord Stream 2 will mean cheaper, cleaner and more abundant energy to meet the continent’s needs for decades to come. Opponents — including the United States — see something far darker: a geopolitical power play that gives Russia leverage to punish wayward neighbors and to blackmail European powers who may talk tough against Moscow but are growing ever more reliant on its gas to keep the lights on.

Even if that is not the intent, the project has already succeeded in one critical Russian objective: dividing the West.

“I’ve never seen a commercial project so intensely debated at the highest levels of European politics,” said Maros Sefcovic, the European Commission’s vice president for energy matters. “This project is really polarizing the E.U.”

Nowhere is the division felt more sharply than in Germany, the pipeline’s planned terminus, where Merkel is the target of an aggressive lobbying effort to persuade her to reverse years of tacit support and throw up a last-
minute roadblock. 

Trump is expected to push the issue when the pair talk behind closed doors at the White House, and a bipartisan majority in Congress has authorized sanctions against the pipeline’s investors — a group that includes prominent German firms.

“Germany hooks up a pipeline into Russia, where Germany is going to be paying billions of dollars for energy into Russia. And I’m saying, ‘What’s going on with that?’ ” Trump said at a White House meeting this month with Baltic leaders.

Merkel, who had long insisted that the project is purely commercial and that she would not stand in its way, caused a stir days later when she said that “political factors must also be taken into account.”

The comments, though cryptic, were cheered by pipeline opponents who inferred that the chancellor intended to use her considerable muscle as leader of Europe’s largest economy to force a renegotiation of the project’s terms and, perhaps, stop it altogether.

Yet it is not clear that she will — or that she could — even as she finds herself isolated from allies urging a tougher stance against an adversary that has invaded a neighbor, interfered in elections and stands accused of carrying out assassinations on European soil.

“There’s a unified, bipartisan approach from the United States. There’s a consolidated majority within the E.U. From everywhere there’s pressure on Germany,” said Norbert Röttgen, chair of the German Parliament’s foreign affairs committee and an outspoken pipeline critic. “But it’s late. It’s really late. I don’t know if it’s too late.”

Germany gave the project final permitting approval last month. Preparatory construction at the quiet German harbor where the pipeline is intended to come ashore began in January. And if the consortium that plans to build the pipeline is nervous about Merkel’s apparent change of heart, it’s not letting on.

“We’re on schedule,” said Jens Mueller, a project spokesman. “We’ve got the permits in Germany and Finland. We expect more permits in the coming weeks and months. All of that gives us the opportunity to construct the pipeline as planned.”

Among the countries that need to give assent is Denmark, where some are challenging the pipeline on security grounds. But if that hurdle and others can be overcome, it would mean Siberian gas flowing from a site near St. Petersburg, beneath the chilly Baltic waters and into northeastern Germany, by the end of next year. 

The route follows that of the original Nord Stream, which was built in 2011. The new pipeline would double the capacity of Russian gas to enter Europe via the Baltic.

Europe is already heavily reliant on Russia, which accounts for nearly a third of the E.U.’s gas imports. For Germany, the world’s largest gas importer, the dependence is especially strong: About 40 percent of the country’s gas comes from Russia.

That figure is expected to rise substantially if Nord Stream 2 gets built. To allies who oppose the project, Germany’s Russian gas addiction creates a dangerous vulnerability for a country that has been tough with Moscow on sanctions — but that also walks a careful line in not antagonizing the militarily far superior power to the east.

“The Russians are playing a long game here. They’ve got the patience, and they’ve got the commitment,” said a senior Western official who spoke on the condition of anonymity. “We really think the Germans are not seeing the signs or don’t want to see the signs of how this could be very bad for Europe’s future.”

The official cited the potential for a Russian military incursion in the Baltics and the leverage that controlling Europe’s gas supplies could offer Moscow.

“Suddenly, everyone tries to move [troops] east, and the Russians just shut off the taps,” said the official, who was not authorized to speak for the record. “That’s a real consideration for NATO.”

Russia has played such games before. It has turned off the gas to Ukraine as a means of pressuring the former Soviet republic whenever it appeared to be drifting toward the West.

Ukraine has been particularly outspoken in its opposition to Nord Stream 2, which could cost the country up to $2 billion annually in transit fees as Russia shifts supplies away from Ukrainian pipes. 

Merkel said this month that she had told Russian President Vladimir Putin in a phone call that Ukraine must not be cut out of the transit business if Nord Stream 2 is built. Sefcovic, the E.U. official, said he was hopeful negotiations could yield a deal to protect Ukrainian interests.

But Ukrainian President Petro Poroshenko — whose country was the victim of a stealth Russian invasion in 2014 — has expressed deep skepticism, saying that Nord Stream 2 represents a “serious danger” and that the pipeline’s backers are complicit in Russian hybrid warfare aimed at weakening Ukrainian national security.

Nord Stream 2, a sister company of the Russian energy giant Gazprom, does not lack for high-profile supporters in Germany. Former chancellor Gerhard Schröder, Merkel’s predecessor, is Nord Stream 2’s chairman. The project boasts investors from across Europe.

Brenda Shaffer, a senior fellow at the Atlantic Council, said there are legitimate reasons to support the pipeline, including Europe’s need to reduce emissions by substituting gas for dirtier fuels such as coal. But those arguments tend to get drowned out by geopolitics. 

“It’s become a litmus test for everything you think about Russia,” Shaffer said. “If you support it, then you’re not tough enough.”

Critics also ignore that Europe has more energy options than it did several years ago, given the construction of liquid natural gas (LNG) terminals, said Kirsten Westphal, a senior associate at the German Institute for International and Security Affairs. That could limit the potential for Russian leverage.

“You now have the possibility to switch away,” she said. 

Mueller, the project spokesman, said commercial competition, not geopolitics, is at the root of much of the opposition to the pipeline. Other countries — including the United States — want to sell LNG to Europe. “A big share of the political argumentation is aimed at undermining a future competitor,” he said.

There’s no hint of that controversy in Lubmin, the bucolic, pine-shaded beach town where the original Nord Stream comes ashore — and where work has begun to get ready for its twin.

The proposed pipeline may be causing a rift in the Western alliance. But in Lubmin, a town an hour’s drive from the Polish border that was once part of communist East Germany, it just looks like good business. 

“People here see Russia as a reliable trading partner,” said the town’s mayor, 51-year-old Axel Vogt. “We don’t want to get involved in U.S. and E.U. politics. We don’t know what their interests are.”