US Bans Anthropic's AI Model Fable 5 Over SK Telecom Concerns

The Trump administration’s decision to impose strict export controls on Anthropic’s latest AI model, Fable 5, stems from concerns over the startup’s collaboration with South Korean telecom giant SK Telecom. A report by Wired reveals that the ban followed a dispute over SK Telecom’s access to Anthropic’s advanced Claude Mythos model, which raised alarms within the US government.

US officials were reportedly troubled by alleged ties between SK Telecom and China, a concern that escalated when Amazon CEO Andy Jassy flagged potential vulnerabilities in Fable 5. Amazon researchers reportedly managed to “jailbreak” the model, bypassing its safety guardrails, which led to fears about national security risks.

Earlier reporting by The Washington Post had highlighted concerns over an unnamed South Korean telecom company. In response, SK Telecom denied any verified links to China and dismissed the allegations as baseless.

Despite Anthropic viewing SK Telecom’s access to Claude Mythos and Amazon’s security concerns as separate issues, the White House ultimately concluded that the company could not be trusted to safeguard its cutting-edge AI technology technology. The government mandate restricting access to the models exclusively to US citizens did not explicitly mention China or SK Telecom, but the series of events led to heightened scrutiny.

As a result, the Trump administration ordered Anthropic to revoke access to both Mythos and Fable 5 for all foreign nationals, including those within the United States. Facing logistical and privacy challenges, Anthropic opted to take the models offline entirely, leading to a deadlock in negotiations between the company and the White House.

SK Telecom’s involvement in Anthropic’s Project Glasswing, which initially limited access to Claude Mythos to a select group of trusted entities, became a focal point of the controversy. The telecom giant was included in the program alongside other prominent Korean institutions like Samsung Electronics and the Korea Internet and Security Agency. SK Telecom’s deep financial ties to Anthropic include a $100 million investment in 2023 aimed at developing telecom-specific AI models.

While SK Telecom itself has minimal operations in China, generating only $1.9 million in revenue there in 2024 and employing seven people, its parent company, SK Group, has significant interests in China’s energy and semiconductor sectors.

SK Telecom’s historical connections to China include a joint venture called UNISK with state-owned China Unicom in 2004 and a subsequent $1 billion bond investment in 2006. Although SK Telecom divested most of its stake in UNISK in 2009, a 2025 SEC filing shows it still holds a $17 million financial interest in the venture.

This backdrop is particularly sensitive, given that the Trump administration previously blacklisted US investments in China Unicom due to alleged military ties. Additionally, the FCC has proposed a ban preventing US telecom companies from interconnecting with China Unicom over national security concerns.

The situation underscores the complex interplay of technology, geopolitics, and national security in the AI sector, with Anthropic’s Fable 5 at the center of growing tensions.