It’s hard for a keen political observer, let alone a casual one, to determine when President Trump is seriously pushing forward a policy proposal, setting up leverage to negotiate a settlement, or simply mouthing off. This uncertainty is a unique gift that Trump alone has, which makes his supporters love him, his detractors hate him, and his negotiating partners wary of him. While “make Canada the 51st state” seems to be in the “joke” category, “rename the Gulf of Mexico,” “abolish the penny,” and “shut down the southern border” were all policies that pundits underestimated his seriousness on. The acquisition of Greenland jumped from joke to serious policy proposal this week.