>you can't just reverse that decision on a whim.

You definitely can when your own existence/security is under threat.

In such cases, you can override people's idealist wishes since keeping borders defended and citizens safe, fed and warm in trouble times is more important to maintaining a stable economy and society long term, than rolling with the idealist fantasies of not using nuclear energy that people wished for when times were good.

But 30 years of not taking military/defense and energy self sufficiency seriously, is costing the EU taxpayer greatly now. It's a tragedy of the commons.