South Korea wants to punish its biggest online retailer for a massive data leak. The U.S. is stepping in to shield Coupang, because even though it operates almost entirely in South Korea, it is registered as an American company.

Since last November, Coupang has been under fire after South Korean regulators found a former employee used a stolen security key to access personal information from 33.7 million accounts, about two-thirds of the population, over months without anyone noticing. South Korea’s science ministry called it a management failure, and regulators have opened separate investigations into algorithm rigging and unfair business practices.

Fifty-four Republican lawmakers wrote to South Korea’s ambassador on April 20, accusing the country of a “whole-of-government assault” on Coupang after the data breach. The letter accused South Korea of unfairly raiding Coupang’s offices, imposing fines and tax audits, threatening to revoke its business license, and pressuring South Korean public pension funds to dump their Coupang holdings.

The dispute underscores a bigger question about who gets to regulate a company that dominates one country’s market while registered under another’s laws. For the U.S., the ability to shield Coupang — a New York Stock Exchange-listed company with significant American backing — signals how well it can protect its business interests on foreign soil.

“The U.S. government and Congress are mandated to protect U.S. companies, and advance our interests overseas, so it is logical and normal that the executive and legislative branch are weighing in to support Coupang, and also U.S. business interests in Korea more broadly,” Henry Haggard, senior adviser at WestExec Advisors and former minister counselor at the U.S. Embassy in Seoul, told Rest of World.

Ninety-six South Korean lawmakers fired back in a letter to the U.S. ambassador on April 28, saying “the investigation and adjudication of alleged criminal conduct are the exclusive authority of a sovereign state.”

Greenoaks and Altimeter Capital, two of Coupang’s U.S. investors, sued the South Korean government in January, alleging the investigation was discriminatory. Coupang also spent more than $1 million in early 2026 lobbying U.S. lawmakers to protect trade and investment ties with South Korea.The U.S. congressional letter argued Coupang is the latest in a pattern, citing South Korea’s treatment of Apple, Google, and Meta. South Korea had fined Google $177 million in 2021 for restricting phone makers from customizing Android, and has fined Meta at least three times since 2020 over data privacy issues.

Behind the trade dispute is another U.S. fear — that every move against Coupang is a win for China.

“If your government’s current efforts to push American companies from the country’s online retail market succeeds, then the vacuum would quickly be filled by Chinese platforms like Temu, Alibaba, and Shein, who receive preferential treatment due to their lucrative partnerships with Korean companies,” the U.S. congressional letter stated.