America has ample supplies of natural gas, oil etc. and so doesn't need to turn away from fossil fuels to be energy independent. Whereas in Europe we do as there isn't much natural gas or oil and even the coal that remains is difficult to extract and thus less economical.
In the short to medium term. The natural gas, oil etc. are in fact finite resources created over a tremendously long period of time in pre-history and so once they run out you're done.
You could run nuclear power plants much longer, perhaps even indefinitely, and of course wind and sunlight are renewable, Sol doesn't give a shit what we do, it's going to shine on the planet and cause winds here until long after we're dead. But the dinosaur juice runs out, it's a quick burst and then if you didn't transition too fucking bad game over.
And to do it all before we cook ourselves in greenhouse gases.
I'm rather optimistic about it but it does seem that most people don't fully grasp the importance of such a transition.
The US is a large place with a lot of potential for extraction, so if you ignore the bit where the hostile climate kills them instead they could keep extracting at similar rates for maybe a century or more, but it does run out.