Which enemy of America should be the biggest concern?

China. China plays the long game, and will be patient to wait for America to progress all the way to Greece-like levels of social justice and social welfare. They will help us along the way where it can do so without starting a major war, at least while we are militarily superior.

I think that ISIS is a bigger threat than the rest of Asia combined. They have huge piles of money and basically no government to run, lots of emotional support and a total lack of morals or values. All the other countries at least have some values...

Our country is our greatest enemy. We as a nation need to stand up to the politicians that are trying to destroy us. We all know who they are, let's vote them out of office. Work on our issues first then help other countries.

SPC Rory J. Mattheisen The proletariat!

Although any list I would create to answer that question would for a military and/or foreign policy standpoint include every country or terrorist group listed. but I would hasten to add this add to add include the current administration. But, in 1970, on Earth Day, the popular syndicated comic strip, POGO, said in it that day strip, "We have met the enemy, and he is us!"

North Korea is ruled by a Mental Deficient Mad Man. That is problematic considering for it's size it has the Largest Military.