...that was not a stellar moment in US foreign policy.
Cuba...well...we pissed them off...they picked a guy who decided it was better to align with our principle enemy. While I can understand the overall reasons for doing so...allowing nukes to be shipped there and pointed at us was..well...ill-advised considering their proximity.
And with Iraq...we may patrol the shipping lanes...but I have not...to date...heard of us threatening any humanitarian aid (meds and food)
And we would threaten...and have...companies who do business against our will...but it happens all the time and we largely do nothing...unless the materials in question have military applications...and even them sometimes we do nothing (think China)