Donald Trump says the U.S. needs control of Greenland and the Panama Canal "for national security." Here's why both places are so important.

President-elect Donald Trump wouldn't rule out military or economic coercion, saying the U.S. needs to stop China. Also a factor: climate change.

Still two weeks away from taking office, Trump has begun outlining an aggressive foreign policy with little regard to diplomatic considerations or the concerns of U.S. allies.