(a) The governing body of a public agency may hold an executive session during a regular, special or emergency meeting, in accordance with the provisions of this section. During the open portion of the meeting, prior to convening an executive session, the presiding officer of the governing body shall identify the authorization under this section for holding the executive session and present it to the governing body and to the general public, but no decision may be made in the executive session.
(b) An executive session may be held only upon a majority affirmative vote of the members present of the governing body of a public agency. A public agency may hold an executive session and exclude the public only when a closed session is required for any of the following actions:
(1) To consider acts of war, threatened attack from a foreign power, civil insurrection or riot;