Frontier Models

GPT-5.6 vs Claude Mythos / Fable 5 — two of the most talked-about AI models right now, and the contrast couldn't be sharper. One is tethered to cost — more capability, more price. The other? Stamped BANNED before most leaders even had a chance to evaluate it. As AI decision-makers, the three levers we must always weigh are: ⚖️ Cost — what does it actually run you at scale? 🧠 Capability — does it move the needle on your use cases? 🔒 Control — who governs access, and what happens when that changes? The Mythos/Fable 5 situation is a wake-up call: capability alone isn't a strategy. Governance and access risk are just as critical to your AI roadmap as benchmark scores. Which trade-off is your organization navigating right now? #AI #AILeadership #FourthIndustrialRevolution #AIStrategy #EnterpriseAI #LLM #SiliconValley …more

Anthropic's Fable 5 & Mythos 5 – Still Disabled, But the Story Is More Nuanced Than Headlines Suggest - Update 6/19/2026: On June 9, Anthropic released Claude Fable 5 — its first publicly available "Mythos-class" model — along with the more powerful Mythos 5. Just three days later, on June 12, the U.S. government issued an export control directive requiring Anthropic to block access for all foreign nationals. To comply, Anthropic disabled both models globally for every user. As of today (June 19), access remains fully disabled. Anthropic has described the situation as a misunderstanding and is actively engaged with the Commerce Department to restore availability. The company has also floated proposals for closer ongoing coordination with the administration on security matters. The triggering event was research — reportedly shared by Amazon — showing a prompting technique that could bypass some of Fable 5's guardrails. However, cybersecurity experts who reviewed the findings (including former government advisor Katie Moussouris) have clarified that this was NOT a traditional high-risk jailbreak. It was a narrow "Defense Oriented Prompting" method — essentially asking the model to "fix this code." The technique surfaced only minor, previously known vulnerabilities and did not demonstrate novel or catastrophic misuse potential. This episode highlights the growing tension between frontier AI capability, export controls, and responsible deployment — with real implications for companies building or using advanced AI systems. I've published a deeper analysis covering the timeline, the technical details behind the reported technique, the government response, and what this means for AI governance and organizations navigating these risks. Full piece here: https://kentkaufman.substack.com/p/from-mythos-to-fable-and-now-to-government What are your thoughts on how export controls should evolve for frontier models? I'd value perspectives from those working in AI, security, or regulated industries. …more

Update: The U.S. Government's Export Control Order on Fable 5 & Mythos 5 In the days since my original post, the situation has escalated. On June 12, the U.S. government issued an unprecedented export control directive ordering Anthropic to block all foreign nationals from accessing Claude Fable 5 and Mythos 5. Because real-time citizenship verification at scale is not feasible, Anthropic had no choice but to shut down both models globally — just three days after their public launch. Anthropic has complied with the order but is pushing back hard. The company disputes the severity of the reported jailbreak, argues that the government's process lacked transparency, and has warned that this approach could effectively halt new frontier model deployments across the entire industry. Meanwhile, Anthropic executives have been in active negotiations in Washington with senior officials, including Commerce Secretary Howard Lutnick. Reports indicate that the security findings that triggered the government's rapid response originated from researchers at Amazon, with CEO Andy Jassy reportedly raising the issue directly with the White House. I've added a detailed Post Script to the original article covering Anthropic's response, the administration's position, Amazon's role, and the broader implications for AI governance and organizational strategy. 🔗 Read the updated post with the new Post Script here: https://kentkaufman.substack.com/p/from-mythos-to-fable-and-now-to-government This episode underscores how quickly access to frontier AI capabilities can change due to geopolitical decisions. How is your organization preparing for this new level of model access uncertainty? …more