Filling up the plane's tank...

Since fuel is really cheap in certain parts of the world, like
Venzuela or UAE, wouldn't it make sense for a US airline to have long
distance routes to those places? They could then fill up the tank
really cheaply, at least on one end of the journey.

I wasn't suggesting tankering, but really just running flights with
regular fillups to places with cheap fuel. The airline buys expensive
fuel here for the trip to that country, but then gets to buy cheap
fuel for the return. Maybe the cheaper fuel would make that flight
more cost effective, and the airline could promote tourism to that
country to fill up the flight.