A country is more than just a collection of people who live within certain borders. That is the most empty way to define a country. A country is more like a group of people who share common experiences, like a history and mythology, and these are things people will fight to protect. In the United States, we honor our military not only for keeping us alive, but for preserving our way of life. Although history and mythology seem intangible, they are considered a part of life itself, something that gives meaning to life.
It would be wise for a country to make it's history and mythology secure. Not to say that these things should be imposed on the rest of the world. But rather just to remember and teach these things to the future generations. A country needs it's history, it's important for the culture of the world.
While I am sure all Presidents look at history to help guide them with all the tough choices they have to make. Others probably look at the mythology too, and use that to help base their decisions. One could only imagine that our leaders use every possible resource to help them make the right decisions, as far as National security goes.
I do not believe a country's national security includes its history and mythology. Firstly, the majority of history, regardless of where it happened, has nothing to do with current security. For instance, the historical facts of America, like the fact we started as colonies, has little bearing on a daily basis. Mythology is even less important when considering natural security.
I do not believe a country's national security also includes its history and mythology. A country's national security should all be about the real life and present issues in which it is being issued with that puts the country and its nations in danger. I think that logic and common sense should be more important in regards to such a topic such as national security.