Since the dawn of history the "state" was always the biggest threat to the safety of it's "citizens", not external aggression.
The inverse is also generally true. The largest existential threat to the USA as a political entity is another civil war. It is currently the best protected country against invasion in history.
The inverse is also generally true. The largest existential threat to the USA as a political entity is another civil war. It is currently the best protected country against invasion in history.