Why should they?

To get an easy win compared to Iran just before the midterms? Of course, it could end up in a mess, but it's a mess already anyway.

They've been farming the Cuba thing since the boomers were children. Every election there are bitter Floridian descendants of Cuban exiles to court. It would be insane for them to permanently resolve the issue, and any actual resolution would inevitably be a disappointment to them.