The problem with having a corrupt, career criminal, midwit, who lies constantly and who can't read a speech without sounding demented as President is that even when you do have a good idea or a good strategy, people will assume your real motives are something else.
In the case of Greenland, the security concerns are reasonable. There are often Russian vessels within its waters for no good reason, and Denmark/Greenland don't do anything about it. Someone who knows, told me that an invasion force of about 800 people would be enough to take it over, as it stands.
But rather than discuss sensibly how US security presence can be increased and have an adult conversation, the whole thing ends up sounding like a typical Trump gravy train.