France was strongly pro-nuclear because it became a national security issue. They were at a huge disadvantage to Germany for most of the 19th and early 20th century because they lacked coal reserves or their coal reserves were close to the border with Germany. Energy independence remained a huge issue during the Cold War as well.

In the US, we've always been flush with oil even when the Arab Embargo hit. It's just been more expensive to extract than Saudi Arabia. Sadly, it became a dependency for us and part of Americana to have your own car and go where you want. Mass Transit and more sustainable ways of living never took off in most of America; all things which drive demand for centralized sources of energy like nuclear.