A blockade on oil imports is leaving Cuba with few resources. US Secretary of State Marco Rubio wants Cuba's government on its knees. The situation has become even more tense following a fatal confrontation at sea. In the early hours of Wednesday, a speedboat carrying 10 Cuban exiles drew near the coast of Cuba. It appears to have set out from Florida . It was intercepted by a patrol boat of the Cuban coastguard. There was an exchange of fire that left four peo... [5480 chars]