What action should be taken if a classified meeting has participants without appropriate clearances?

The recommended action when a classified meeting has participants without the required clearances is to cancel or relocate the meeting. This is crucial for maintaining the integrity and security of classified information. Only individuals who have the necessary security clearances and a valid need to know should be privy to sensitive discussions. Proceeding with such a meeting, regardless of the additional security measures that might be introduced, would put classified information at risk of unauthorized disclosure. Holding the meeting in a public space would expose sensitive information to individuals who are not authorized to access it, which is strictly against security protocols. Briefing unauthorized participants on the risks does not rectify the issue of them being present in the first place. Therefore, the safest and most compliant course of action is to cancel or relocate the meeting to ensure that all participants are properly vetted.