The "America First" slogan often used by candidate Donald Trump in his first and second presidential campaigns might sound on its surface to indicate disengagement from global affairs and a focus on domestic priorities. So, it may seem puzzling that President Donald Trump is talking about annexing Greenland, an autonomous territory of Denmark, a NATO ally; Canada, a sovereign country and a NATO ally; and retaking the Panama Canal.
If, however, you see Trump's pronouncement within the context of global economic and military competition in what he perceives is a zero-sum world (a win by one side must be a loss by another), then this kind of rhetoric begins to make sense. Such a view actually implicitly presumes that resources available to global society are finite or, at the very least, worryingly scarce and therefore must be produced domestically for security reasons or extracted willingly or unwillingly from other countries.
Trouble is, there is a very long list of important minerals that the United States must get either partially or wholly from other countries in order to maintain the smooth functioning of its modern technical economy. In addition, America, which had previously been a breadbasket to the world, is now a net importer of food—though this is on a value basis, not necessarily on a tonnage or calorie basis.