(a) Scope of affirmation of authority Subsection (b) of section 394 of title 10, United States Code, is amended by inserting defense of critical infrastructure of the Department of Defense, after force protection,. (b) Amendment to definitions Subsection (f) of such section 394 is amended— (1) by redesignating paragraphs (2) and (3) as paragraphs (3) and (4), respectively; and (2) by inserting after paragraph (1) the following new paragraph (2): (2) The term critical infrastructure of the Department of Defense means any asset of the Department of Defense of such extraordinary importance to the functioning of the Department and the operation of the armed forces that the incapacitation or destruction of such asset by a cyber attack would have a debilitating effect on the ability of the Department to fulfill its missions..