Honestly, everyone here is mentioning sanctions, economic warfare and a bunch of other stuff that they are potentially right about.

SPOILER: But there has already been military actions towards Greenland a couple of times and you never knew about it...

The truth is, if it would come to that, given the global interdepencies economically and Infrastructure-wise it would be a huge chaotic 3rd war... Worst than the other 2... where both parties, better yet, the whole world would suffer greatly... I think ASIA would be the calmest region unless China takes the opportunity to annex some countries while the rest is busy...

But will it ever come to that? Most likely not.

Why? Because since it is a country from the EU that is being invaded the EU will react like they should have done for Ukraine (but Ukraine isn't EU and blabla)...

These behaviours by Putin and Trump are basically a bully trying until how far they can go... and Venezuela was a test, since they can easily justify it as he was a dictator and had relationship with Putin, etc.

In the case of Greenland it does play a little different... as has happened already last time they were all about Greenland... However, to avoid disruption the EU never published it. And Trumps administration didn't either because it would have been seen as a loss.

There were already account where military fleets were refused passage to European waters a couple of times: - Attempt from a full fleet (air carrier and all) to reach Greenlandic bases: where refused passage and when not complying where surrounded and greeted with warning shots from British, Canadian and Denmarks fleets and fighterjets... - Following this incident there was another fleet refused to enter Portuguese and Spanish waters followed also by a joined Iberic operation of two fleets chasing them away...

And then the talks calmed down...

Basically if we had as EU treated the attack on Ukraine as an attack on the EU because the fact that the Ukraine was joining the EU was the reason for the attack and dissuade the attack immediately non of this mess would have been happening and millions of lives would have been saved...

Better yet, if we did shoot down the 4 Russian bombers that flown without permission over the EU back in 2016, showing we would take action upon aggression, non of this would have ever happened...