What type of information requires pre-approval before disclosure to foreign nationals?

Classified information is highly sensitive and is safeguarded for national security and operational integrity. Disclosure of classified information to foreign nationals requires careful scrutiny and pre-approval to ensure that sensitive military and intelligence capabilities, plans, and operations are not compromised. This is because classified information could potentially provide insights into U.S. defense systems, strategies, technologies, or operational methods that adversaries might exploit.

In contrast, public information is available to anyone and does not require any special clearance for disclosure. Open-source information is also freely available and can be accessed without any formal disclosure process. Historical data varies in sensitivity, but it often lacks the immediate operational implications that could arise from sharing classified information. Thus, the requirement for pre-approval specifically applies to classified information due to its potential impact on national security.