The biggest threat to the U.S. is not China, Russia or the enemy within (Muslims, socialists, etc); it's another emerging super power with a larger economy, bigger military power and higher productivity, and it's a few miles away. Cuba. U.S. sanctions on Cuba
“The West won the world not by the superiority of its ideas or values or religion (to which few members of other civilizations were converted) but rather by its superiority in applying organized violence. Westerners often forget this fact; non-Westerners never do.” —Samuel P. Huntington, The Clash of Civilisation and the Remaking of the World Order, 1996, p. 51