1. The technical solution relies heavily on fantasy.
2. It is not needed. We have no significant power transmission across the low lying fruit of continental America or Eurasia, and those lines are built! Why bother crossing an ocean?
3. Why not cross Greenland and the North Sea and its islands? Under sea cables are expensive.
4. Why not cross the Bearing Strait?
There was a big solar project proposed in Australia's outback to supply Singapore but never got off the ground perhaps advances in glass / dc infrastructure could change the calculations. Same story for Sahara solar supply to Eu.
A lack of need is not the problem here.
Solar Sahara powering Europe makes sense.
Solar Sahara powering the North East does not.
(yet, I guess)
The US abandoned trade as a means to peace
They see the difference in how we treat Iraq/Libya and North Korea.