To get the full treatment on the topic of National Security from the U.S. point of view, take a look at my series of general FAQs I wrote for Quora at the following link:

https://www.quora.com/topic/National-Security/faq

One of the FAQs provides the U.S. Government definition of National Security, as follows:

Within the context of how the United States defines National Security, it was developed and promulgated via Joint Publication #1 by the Department of Defense, Joint-Chiefs-of-Staff. The meaning is: A collective term encompassing both national defense and foreign relations of the United States with the purpose of gaining: a. A military or defense advantage over any foreign nation or group of nations; b. A favorable foreign relations position; or c. A defense posture capable of successfully resisting hostile or destructive action from within or without, overt or covert.

In terms of a “legal” definition of National Security either in the U.S. Code of Federal Regulations (CFRs), or anything based on a Federal District, Appeals or Supreme Court ruling that might create “case law,” you will not find anything. The reason why is the term, by its very nature, is too broad, and any level in the U.S. court system would be committing “judicial suicide” if they attempted to render a felony trial verdict based on an attempt to fully encapsulate a definition of National Security.

Not trying to be flippant, but, attempting to create a single, legally binding definition of National Security that could hold up to an ultimate determination by the U.S. Supreme Court, would be just as difficult as to pin down as legally defining the term “Chocolate Donut.”

Seriously, take a look at my National Security FAQs. Part of the problem with trying to pin down a legally binding definition of National Security is simply that it is a moving target that is constantly evolving. My FAQs denote some of the more recent developments that now pose a National Security threat that no one would have dreamed of 50–60 years ago. Here are a few examples of what I mean:

1. Global Climate Change;
2. Trans-National Crime;
3. A Global Disease Pandemic;
4. Cyber-based Infrastructure Threats;
5. Space-borne Threats. And this is not just “Star Wars” stuff with killer satellites and lasers. The U.S. is the ONLY country in the World to track the tens of thousands of pieces of space junk, defunct satellites, micro-meteorites, et al, that could potentially enter the earth’s atmosphere, or possibly collide accidentally with an important spacecraft up there. A burned-out Russian satellite has already collided with an American in-use satellite that before the collision, there were just two objects, and now the debris has made thousands of objects.

If you go back to the 1930s, not only were the threats listed above either unknown, or considered non-threatening, but, no one had an inkling about a nuclear holocaust being a National Security threat either.

These are just some of the things we have added to the National Security threat list since World War II. I am sure there is more to come, and our understanding of what constitutes National Security will continue to evolve, too.