Greenland is a Danish territory, Denmark is already in NATO. Cuba is an ex-USSR ally, since USSR was sanctioned and that included allies, Cuba was sanctioned as well. Cuba is also sanctioned because of their own politics, similar to how Milosevic's Yugoslavia was.

Russia is threatening a direct military invasion to present-day and potential future NATO and EU members. When has the EU done the same to any of your listed countries/territories? When have the US said they will invade a country for simply allying with Russia or the BRICS?