On Monday, hundreds of workers at Amazon’s (AMZN) warehouse facility in Leipzig, Germany went on strike. It was the latest protest in a nearly year-long battle between German union Verdi and the online retailer. Hundreds of workers walked off the job at German distribution centers in November and December; the protests started last spring. The Verdi union is demanding that Amazon pay its distribution center workers the standard wages for employees in the country’s retail sector.

Amazon has argued that its distribution center workers — who sort goods and load and unload trunks — are not retail employees but instead belong to the logistics industry and that the company pays them well according to that sector’s standards. “Our employees earn toward the upper end of the pay scale compared to other logistics companies,” it said in a statement provided to Fortune on Monday. “The entry wage for an Amazon employee in Germany is 9.55 euros an hour, plus bonus, insurance, and pension pay. After one year employees earn more than 10 euros, and after two years, employees get shares in the company.” Amazon added that in all of its “logistics centers” it has “employee representation — either as works councils or as employee committees with whom we work closely together to make sure employees’ interests are considered.”

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Amazon, of course, has had its fair share of run-ins with unions on its home turf. In 2000, it shut down a call center where the Communication Workers of America started a campaign to unionize 400 customer service employees. In other instances it has provided managers with anti-union materials to distribute to workers. In January, maintenance and repair technicians at a Middletown, Del. warehouse voted down union representation.

Amazon’s organized labor battles in the U.S. — where union representation is 11% — pop up and then tend to go away quickly. That’s not the case in Germany, where unions represent about 18% of the workforce and companies face stricter worker protections.

“Amazon seems to be clashing with the German employment culture, in which, of course, unions — while not as powerful as they once were — are significantly more powerful than those in the United States,” says John Logan, associate professor of labor and employment studies at San Francisco State University.

In failing to synch with the German work environment, Amazon is not alone.

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Wal-Mart (WMT) — another U.S. company known for its anti-union stance — ran into similar union opposition after entering the German market in 1997. The company’s ethics code, which prohibited inter-office romance and encouraged employees to report improper workplace behavior, didn’t sit well with the Verdi union, which organized all of the 90 or so Wal-Mart Supercenters in the country. Wal-Mart, whose merchandise didn’t jibe with Germans’ frugal and demanding shopping sensibilities, eventually pulled out of the country by selling its chain to rival Metro in 2006.

Though Amazon’s run-ins with Germany’s retail worker union mirror Wal-Mart’s, the online retailer seems to have a lot more at stake. While Wal-Mart failed to gain traction in Germany — seven years in it had captured just 2% of German food sales and sold its stores at a $1 billion loss — Amazon’s sales have soared in the country — by about 12% in 2013 — making Germany the online retailer’s second-biggest market behind the U.S.

“The trade unions have a lot of bargaining power,” says Lowell Turner, director of The Worker Institute at Cornell University. “Germany is a big market for Amazon. This is going to keep happening until Amazon gets its act together.”