Right now North Korea's missiles have an estimated range of 3600 miles. That is why China is pushing so hard for them to discontinue their nuke program.
Speaking of China, they are the next potential threat. If they were to switch their production over to a war footing it would make the US's WWII war machine look like kids playing with blocks. It really is just a matter of time before China starts trying to expand. When they do none of their neighbors will be able to stand up to them in a conventional war. If the US steps in to stop them it will (yet again) be the bad guy in the eyes of the world sticking their nose in where it doesn't belong. Yet if the US does nothing the world will cry foul that the US is 'allowing' China to act aggressively.
We catch Hell either way.
