Although I agree with you in principle, not all countries in the EU will suffer equally if the gas and oil lines are cut.Not going to be an EMP. No nukes. That would be a death sentence for the world. No way there would not be massive retaliation. Just cut the gas and oil lines. Economic security is national security. Cut off trade. Good bye EU. Even worse, if they actually succeeded in getting all their energy needs from Batteries, it becomes MUCH simpler. I don't know what they are thinking. You just cut the supply lines from the Congo and China. Good bye. No one needs die in actual fighting. Think surrounding the Castle and starve them out. Old school Medieval Castle Warfare. You wait them out.
France has 58 nuclear power plants which supplies almost 73% of that countries electricity. Germany on the other hand only has 8 nuclear power plants (all to be phased out by 2022) which supplies about 12% of their current electricity needs.
France's renewables and fossil fuels accounted for 17.8% and 8.6% of the rest respectively.