Answer: The level of government in which I think should be in charge of security is going to have to be federal. Because the federal government deals with the nation’s affairs and laws. Security from foreign enemies is a national concern meaning that the federal government should take care of the nation’s defense. Which they do of course. The Department of Defense is an executive branch department of the federal government of the United States charged with coordinating and supervising all agencies and functions of the government concerned directly with national security and the United States Armed Forces.
Its fair to say that "it is designed to bend like a willow" because the constitution was made fairly flexible, and this gave the government bandwidth to extend its power to meet new situations.