Can Trump seize Greenland and the Panama Canal?

Two weeks before his second presidency begins, Donald Trump has laid down his hopes to take control of Greenland, the Panama Canal, and even Canada. He told reporters the United States needs to acquire the Danish territory for national security reasons, and has threatened heavy tariffs on Denmark if they don’t agree.  Today, ANU professor of International Law Don Rothwell on what Donald Trump wants with these territories, and how far might go to take them. Featured:  Don Rothwell, professor of international law at the Australian National University