A Russian tanker carrying 270,000 barrels of diesel fuel, which is under US and EU sanctions, spent weeks trying to reach crisis-hit Cuba, which is also under US sanctions, as well as amid what's essentially become a full energy blockade, but has failed to reach the island nation and turned southward toward Brazil. The exiled Russian outlet, The Insider, has detailed the following based on maritime tracking data: The Russian-flagged tanker Universal (IMO: 9384306), which had been drifting for almost a month in the Sargasso Sea approaching…