I disagree. The greatest threat to America is partisan information distributors. The people who give us information on the broadcasting networks and on the internet are biased, and they have continuously used this power to convince Americans to make very bad mistakes. (Bill Clinton, Barack Obama, and almost Hillary Clinton.)
The information controllers are our greatest threat.
Those who control the minds of kids from before kindergarten (think Sesame St) through high school have a profound effect on the future.
Think what Apple did with their computers. Apple practically gave them away to elementary schools. Every child was exposed to MACs, not PCs. What do the Millenials use now? MACs.