Here's an interesting "what-if": Suppose John Smith is a dual-citizen of an EU nation (jus sanguinis) and the US (jus soli) (and say his permanent residence is in the EU, but he does own a vacation home in Colorado - he likes to ski, but has an aversion to Switzerland ). Mr. Smith is a management consultant, and the majority of his income is earned in the EU. He's paid in euros, and his primary bank is EU-based. Mr. Smith, being a well-off globe-trotting sort of guy, has a US-based bank account as well (which he uses to pay the mortgage on his vacation home) - it's mostly funded by his EU work, but he does periodically consult with US-based folks who pay him in $, and he puts his US-earned income in this account.

Is he in violation of the policies if he flies from the EU to Havana, spends his euros, flies back to the EU, then comes to the US a few weeks later?