• NSA releases guidance on zero trust for operational technology systems.
• Guidance aims to prevent catastrophic impacts on national security and public health.
• Zero trust principles assume adversarial breaches and verify users and devices.
• Adoption of zero trust is essential for securing legacy OT systems.

The NSA's guidance may indicate a growing concern about the vulnerability of operational technology systems to adversarial attacks. The adoption of zero trust principles could strengthen protection against unauthorized access and lateral movement, which suggests a shift in cybersecurity priorities. This guidance may also signal the importance of integrating zero trust into critical infrastructure, which could have significant implications for national security and public health.