All of those are big threats, no doubt, but I've got my eye on a country we've had trouble with before--GERMANY.
The reason I say Germany is our biggest threat is due to the Euro. France and Germany were in cahoots in creating the Euro. They created the Euro to force all the European nations to come under one currency so the Germans and the French could "currency-gouge" the rest of Europe and force them to break loose of the grip of the Euro. Plus, in my opinion, Germany did not learn its lesson from World War II and the United States failed to completely stabilize the country mainly because stupidly got ourselves into a Pacific theater with Japan. (Japan wasn't our biggest enemy in WW2, we made them our biggest enemy.) If America had done things right like befriend Japan (they wanted to be our friend in the late 1930s), we may have been able to avoid Pearl Harbor. Since Pearl Harbor happened our focus had to mainly shift out to the Pacific and thus the European theater ended a good 5 months before the Pacific theater. We didn't treat the Germans with a whole lot of respect coming out WW2 and during the Cold War. That's part of the reason they decided to initiate the Euro some 50 years after the suicide of Hitler. I can very easily see another German attack on France in the coming years and I can see them linking arms with Italy again and plunge the world back into World War 3 in the next 10-15 years.
LOL. No.