Headline: The European 2030 climate and energy package: do domestic strategy adaptations precede EU policy change?

The European Union’s 2030 climate and energy package introduced fundamental changes compared to its 2020 predecessor. These changes included a stronger focus on the internal market and an increased emphasis on technology-neutral decarbonization while simultaneously de-emphasizing the renewables target. This article investigates whether changes in domestic policy strategies of leading member states in European climate policy preceded the observed changes in EU policy. Disaggregating strategic change into changes in different elements (goals, objectives, instrumental logic), allows us to go beyond analyzing the relative prioritization of different goals, and to analyze how policy requirements for reaching those goals were dynamically redefined over time. To this end, we introduce a new method, which based on insights from social network analysis, enables us to systematically trace those strategic chances. We find that shifts in national strategies of the investigated member states preceded the shift in EU policy. In particular, countries reframed their understanding of supply security, and pushed for the internal electricity market also as a security measure to balance fluctuating renewables. Hence, the increasing focus on markets and market integration in the European 2030 package echoed the increasingly central role of the internal market for electricity supply security in national strategies. These findings also highlight that countries dynamically redefined their goals relative to the different phases of the energy transition.