That gets at an interesting point that if one country depends on energy from a far distant country for part of the day, then the defense of those power lines ha

That gets at an interesting point that if one country depends on energy from a far distant country for part of the day, then the defense of those power lines has immense geopolitical significance; similar to oil and gas pipelines. Maybe the solution is to keep a lot of dirty petroleum or coal-based generation capacity around to use in an emergency or war, but don't actually use it. As usual, there's a trade-off between efficiency and resilience.