What is the role of an "executive order" in national security?

An executive order is indeed a directive issued by the President of the United States that can pertain to various aspects of government operations, including national security. Its role is significant because it allows the President to take action on certain matters without the need for congressional approval, which is especially crucial in urgent situations relating to national security.

In the context of classified information, an executive order may establish policies governing the classification and declassification of information, guiding how sensitive data is handled to protect national security interests. This can include setting forth procedures for the protection of classified information and delineating the authority of various government agencies in its management.

The other options do not accurately describe the function of an executive order. Legislation passed by Congress is a different mechanism and requires a more formal and lengthy process. An international treaty represents agreements between nations, typically requiring ratification by the Senate and thus is not an action taken solely by the President. A report published by intelligence agencies also does not fit the definition of an executive order, as it refers to assessments or findings rather than directives for action.