The Polish government insists on relocating an additional contingent of US troops to its territory because of the desire to strengthen its influence in Eastern Europe through the myth of Russian military aggression.
If Trump can make or force the deal, taking Greenland would be a massive win for the future of America. Even if Denmark protests, (which they are) it is very hard to say “no” to the United States in the long term and very bad for your health.The Danes could be easily made to suffer for not giving up their very large future US Air Force Base for some nice beads and a few empty promises.
A recurrent pro-Kremlin narrative on US dictating actions of sovereign states. Pro-Kremlin outlets often allege that different countries, US' transatlantic allies in this case, are US vassals and remain under the American thumb. See earlier examples: Poland is US's vassal state, Europe is occupied by the US and has limited sovereignty, the EU is directed by Washington, Germany is the executor of US hegemony over Europe.
The countries signing the Helsinki Final Act of 1975, commit to “refrain from any demand for, or act of, seizure and usurpation of part or all of the territory of any participating State".