Vitalik: In the AI era, cybersecurity's endgame favors defense, but the transition period will be tough. This critical PHP vulnerability was discovered with the help of AI models from OpenAI and Google, rather than the Anthropic Mythos scan from six months ago. MIRI Chairman Nate Soares called this a heavy blow to the 'defense leads offense' theory. Vitalik Buterin responded, saying he never predicted that defense would automatically take the lead. Discovering vulnerabilities in released software before attackers do is not a sign of defensive superiority. Shifting the balance requires deeper changes like formal verification and streamlined trusted computing bases, which are still in their infancy. This is also a key reason why he supports slowing down AI development. He advocates for investing over 1% of GDP into strengthening security in cyberspace, biology, and the physical world.