The EU has been working on energy policy for a while, but it's been a bit tricky. They've made progress with things like energy market rules and renewable energy goals. People think more EU energy policies are needed for climate change and energy security. This study looked at why EU energy policies change or stay the same. They found that different factors like who's pushing for the change and how the issue is defined can affect what happens. They looked at nuclear energy and renewable energy as examples and found that EU initiatives didn't work well for nuclear but did for renewable energy.