Across the political world, pundits and politicians and diplomats alike are attempting to interpret what Donald Trump's turgid tweetstorms really might mean, policy-wise. For example, Trump is quite sure he wants a "better deal" with Cuba, and has insisted we'll be tearing up the old deal, and really the only certain thing here is that Trump doesn't give a flying damn about Cuba "policy" and is just sailing in whichever direction his blowhard advisers are blowing.
And then, on Monday morning, following a series of blustery anti-Castro pronouncements on the Sunday talk shows by his aides Kellyanne Conway and Reince Priebus, and by Senator Ted Cruz and Senator Marco Rubio, Trump tweeted again: “If Cuba is unwilling to make a better deal for the Cuban people, the Cuban/American people and the U.S. as a whole, I will terminate deal.” A few minutes after that tweet, I asked a Cuban diplomat if he’d seen it. He hadn’t. When I read it to him, he said, in a low voice, “No, no, no. This isn’t going to end well.”
So essentially he's already fouled foreign policy toward Cuba with a series of tweets, doesn't seem to yet have any "demands" for Cuba that would theoretically un-foul it, and is flying the foreign policy plane via his Twitter account because, as during the election, he's more obsessed with self-promoting belligerence than any concrete policy of his own.
Which is precisely the sort of thing that could roil foreign relations not just with foes like Cuba, but with the citizens of even friendly nations that might not feel they deserve to be the subject of a late-night lashing from an impulsive and tantrum-prone manchild.
Anyhoo, it's likely that Trump is indeed signaling what he seems to be signaling here: Cuba can expect a Trump Administration to renege on the negotiated first steps to a softening of relations, but is open to receiving a "something" that would stop them. Perhaps that "something" would be human rights related—but there's not much Raul Castro is likely to be in the mood to give. Perhaps that "something" will be a new Trump hotel concession for his children; that would of course be far easier to arrange.