Reports said SK Telecom was at the center of controversy after the Trump administration on the 12th (local time) imposed an export ban blocking foreign access to Anthropic's top-tier, high-performance artificial intelligence (AI) models, Claude "Mythos 5" and "Fable 5." Wired reported on the 17th (local time) that "the U.S. government's export controls on Anthropic's AI models stemmed from a dispute over granting access to the Mythos model to Korea's telecom giant SK Telecom." This followed a Washington Post (WP) report on the 15th that the White House began considering sanctions after finding, on a list of approved access recipients submitted by Anthropic, a "Korean telecom company" suspected of ties to China. While WP did not name the company that triggered the decisive step to block exports, Wired pointed to SK Telecom.
Wired, in an article titled "Korean telecom giant at the center of Anthropic's Mythos controversy," identified SK Telecom. Wired specifically noted that as the United States raises sanctions on Chinese telecom corporations citing national security, SK Telecom has set up and invested in a joint venture with China's No. 2 telecom operator, China Unicom.
◇ "White House demanded SK Telecom's Mythos access be revoked before sanctions"… Anthropic "complied immediately"
The controversy began when Anthropic on the 9th (local time) launched "Mythos 5" for a select group of approved institutions and corporations to prevent abuse in sensitive areas such as cybersecurity, and released "Fable 5," a Mythos-level model with safety features, to the general public. Summarizing Wired's report citing an Anthropic representative, shortly after the company expanded Mythos 5 access for institutions early this month, the White House raised suspicions that SK Telecom was linked to China and ordered the corporation's Mythos 5 access to be revoked. This was days before the Trump administration's sanctions on Anthropic. Wired reported, "The (Anthropic) representative said the company immediately complied with the (White House) demand, and at that time the U.S. government was not yet threatening export controls on the (AI) model."
Anthropic granted initial access to Mythos 5 only to a small group of trusted institutions through a program called "Project Glasswing." Based on Mythos, Project Glasswing is an international cooperation framework in which corporations worldwide jointly build systems to test and respond to cyber vulnerabilities. According to WP, a few weeks before the Trump administration's export ban on AI models, Anthropic submitted a list of 111 institutions that received priority access to the latest model, "Mythos 5." Then on the 2nd (local time), Anthropic expanded participation in the Mythos-based security consortium, "Project Glasswing," to 150 institutions in 15 countries. WP reported that when Anthropic did not disclose for several days which institutions had newly received access, senior U.S. government officials began considering using export controls to claw back the technology. Citing an official, WP said, "When Anthropic finally submitted the list of institutions, the Trump administration discovered that one institution was a Korean telecom company suspected of ties to China."
The White House's concerns reportedly grew after Andy Jassy, Amazon's chief executive officer (CEO), raised worries to the Trump administration about "jailbreak" vulnerabilities—safety guardrail bypass techniques—found in the Fable 5 model. Anthropic countered that such risks were not unique to its systems. An administration official said this chain of events ultimately led the White House to doubt Anthropic's ability to safeguard AI technology.
An Anthropic representative said SK Telecom's Mythos access and the vulnerabilities flagged by Amazon are separate issues. The representative also added that the letter the U.S. government sent to Anthropic, limiting access to Mythos 5 and Fable 5 to U.S. persons only, did not mention any Korean companies or China. Wired reported that the White House and Anthropic negotiated for days over restoring online access to Claude Mythos and Fable 5 but still remain at odds. Anthropic concluded that restricting access by nationality is practically difficult to implement and implicates privacy concerns, so deactivating the two disputed models for all customers was the better choice.
◇ SK Telecom rebuts "no ties to China"… Wired cites "investment in and joint venture with China Unicom"
SK Telecom, which appeared unaware of the White House–Anthropic dispute, emailed the press on the 4th saying, "We inform you that the company has joined 'Project Glasswing' and obtained early access to 'Mythos.'" SK Telecom has close ties to Anthropic, having invested multiple times. In 2023, it entered a commercial partnership to develop AI models tailored to the telecom industry and invested $100 million (about 132 billion won). Alongside SK Telecom, domestic corporations reportedly included Samsung Electronics and SK hynix as participants in Project Glasswing. As for government agencies, the Korea Internet & Security Agency (KISA) is said to have joined.
Anthropic declined to comment to Wired, and the White House did not immediately respond to a request for comment. Regarding the earlier WP report, SK Telecom said, "Our company has nothing to do with China," and added, "Restrictions on access by foreign nationals to Mythos were applied across the board on the 13th, and we did not receive any separate notice from Anthropic." In response to Wired's report as well, the company repeated that "we have received no separate contact from Anthropic," drawing a line against claims that it was involved in the U.S. government's sanctions on Anthropic.
However, Wired said, "SK Telecom itself does not operate large-scale businesses in China, but the company is an affiliate of SK Group, a large corporations that conducts extensive business in China across various industries, including semiconductors and energy," adding, "As of 2024, SK Telecom's revenue in China was only $1.9 million (about 2.927 billion won) through investment-related activities, and it had only seven local employees, but the company's history of entering China's telecom industry goes back more than 20 years."
In particular, regarding SK Telecom's establishment in 2004 of UNISK Information Technology, a joint venture with the state-owned telecom operator China Unicom, to begin providing wireless internet and mobile content services in China, Wired described it as "the first joint venture between a Chinese corporation and a Chinese telecom operator." It also noted that in 2006 SK Telecom invested $1 billion (154.08 billion won) in convertible bonds issued by China Unicom's Hong Kong-listed subsidiary, which ultimately converted into about 6.6% equity. Although that equity was sold back to a Chinese telecom company in 2009 for $1.3 billion (2.003 trillion won), the company has since maintained small equity stakes related to the joint venture. In its annual report filed with the U.S. Securities and Exchange Commission (SEC) in 2025, SK Telecom listed about $17 million (2.62 billion won) in investments in China Unicom.
Wired said, "In 2021, the U.S. administration of Donald Trump restricted U.S. investment in China Unicom as part of broad measures targeting corporations linked to China's military and intelligence institutional sector," and added, "In April this year, the Federal Communications Commission (FCC) proposed banning U.S. telecom carriers from interconnecting with Chinese telecom companies, including China Unicom, on national security grounds, and China Unicom recently warned that such measures could disrupt global communications networks." In fact, on the 30th of last month (local time), the FCC passed not only an agenda item banning certification testing by Chinese laboratories for all electronic devices, but also a measure prohibiting China Mobile, China Telecom, and China Unicom from operating data centers in the United States. The three telecom companies have already been banned from operating telecom businesses in the United States. The FCC is also considering banning interconnection with carriers that use equipment from Huawei and ZTE.