Even if the US suddenly lost all its fighter jets, naval force, missiles and bombs. How likely would an invasion be in the next 10 to 50 years?
It is quite a big country with a big population, with a practically uninhabited and difficult to cross country in the north, and a poor drug war ridden country with significant amount of jungle in the south. To the west and east are oceans with some thousands of kilometres until the next sizable and properly inhabitated landmass.
So purely in geographics terms, invading and conquering the US is a huge pain.
Now add to it all the issues of the US dominance in global trade and the ramifications such an invasion would have.
The US doesnt need that army or MIC for defense. It is offense focused and it needs to keep murdering people all over the world to keep its wheels turning.
At the end of the day what is considered “terrorism” is political. If we were to use the term in the definitions sense every government is terrorist. Many countries proud themselves on some point in history that would be considered terrorism, like the American Independence or French Revolution.
It is always terrorism if it is challenging the current power and if it wins it becomes freedome fighting instead. Looking at the way climate protests are handled in the UK or Germany it becomes increasingly absurd, as nonviolent acts of civil disobedience are now investigated and charged as “terrorism”.