What part of “government terrified of successful socialist country” didn’t make sense to you?

The US has actively been sabotaging Cuba for 70 years. The fact that they’re doing as well as they are speaks volumes about how well they’d be doing without a super power trying it’s hardest to drive them in to obscurity.

Ah. Now it makes sense.

The amount of oil in a single tanker isn’t likely to affect the US market much. But preventing Cuba from having access to oil would look pretty attractive to a government that’s terrified of a successful socialist nation