Bulgaria, and Romania for supporting the Nazis. Of course, the US president must get congressional permission before launching a military strike.
In the past, presidents have taken military action without Congress’s consent and sometimes without warning. Another problem is that Denmark, a founding member of NATO,
Is now in charge of defending Greenland. Should American aggression occur, Denmark may try to enlist the support of the other members of the alliance.
The US might end up at war with all of its partners or remove the collective defense clause, which would make the whole alliance a fraud,
If it invades Greenland, since NATO was founded as an American-led alliance. Therefore, it would be best for everyone if he never gave it a try.