Venezuela aside for a moment..what if Trump actually take over/occupy Greenland..? Denmark will see that as a hostile action against their territory. It will also mean the end of NATO..all the other members will probably see a takeover as hostile..
Everyone knows Trump says bombastic shit leading into negotiations (or demands).. much of which is never actually intended.. what he wants to set the other party back on its heels at the beginning of the engagement and force them to fight to regain ground... if he doesnt get what he wants, then you have to be concerned about what his next actions might be (he is unpredictable in some ways, and extremely predictable in others)...
The US/Trump isnt going to take over or occupy Greenland.. and was never going to.. He is simply being an asshole (something he is exceptional at) in an effort to get Denmark to continue down the path it is already on..
What Trump wants (and has been extremely clear about) is for Denmark to take the defense of Greenland seriously as well as the defense of NATO (specifically the US and Canada) against russian missile, sub, and/or bomber attacks..
and he has gotten exactly that..
In the last year additional Danish naval forces (frigates and helos) have deployed to Greenland. Denmark has announced the intent to station fighters/interceptors in Greenland soon. Denmark committed to a $4B (USD) increase in spending on artic defense in Greenland (drones, naval vessels, and intercept missiles). Denmark has agreed to place its Artic Command headquarters in Greenland along with another new stand up unit that will be placed under the Joint Artic Command. Denmark is funding underseas communication cables that will physically connect Denmark and Greenland defense units. Denmark is also now planning joint training exercises with other NATO forces specific to the defense of Greenland.
Trump wants this to continue, and for Denmark to go further..
That said, where I think Trump would be more than happy to negotiate back to Greenland being available for the placement of US defense personnel and tools..
The US pulled back radar stations and other defense tools from Greenland when the cold war ended.. there is a bit of argument/debate as to whether or not everyone agreed that the threat no longer existed and that NATO was ok without those personnel and tools in place, or whether or not Europe would step up and start taking responsibility (something Europe clearly fell short on across almost all fronts in terms of defense once the cold war ended)..
Id bet that if Greenland simply responded by telling Trump "if you want over the horizon radar capability and you want missile intercept capability and sub intercept capability in Greenland you are welcome to re-occupy locations X, Y, and Z that you occupied for 40+ years post WW2. We'd love to see a few thousand US troops that would bolster our local economy, and we'd love to see the defense contracts that would service those defense tools that would also bolster our economy. Mr Trump, heres the deal.. you provide the people and the tools, and we'll provide the turf... we're in this together..".. he'd bite on that deal hook, line, and sinker..
and honestly, that sounds like a win-win for everyone... Denmark gets a lot of money.. the US gets improved defense.. and we're not talking about enough people or "stuff" to even cause a minor inconvenience to the residents of Greenland (Greenland has a total of about 57,000 people living there and a land mass of 836,000 square miles)..