Donald I, emperor of the world.

[Pblakeney]

They haven't done anything militarily, yet. They have however tried to destabilise the country enough that Cuba would beg for help.
That hasn't worked and since Donnie has said that he will take control you have to wonder what the next step will be.
He may shed a little more light this weekend with an announcement on "The Shield of the Americas", which will no doubt include Cuba. Amongst others.

Edit:- Note the use of the word "Americas", not "America".

A most likely clue to the bold bit in here...

• According to The New York Times, the Justice Department is investigating Cuba’s leaders and Communist Party officials for drug, immigration, economic and violent crimes, with prosecutors in South Florida aiming to bring rapid indictments. The effort comes as President Trump escalates rhetoric against Cuba and has suggested potential military action after the Iran war, with charges potentially providing a legal pretext similar to the case used to capture Venezuela’s Nicolás Maduro.