II- Literature Review
1) Energy Security in International Relations
Grand theories a) Concept of Energy Security
First and foremost, the concept of energy security is widely
discussed in the literature, but there is no consensus on its definition
(Yergin, 2006; Löschel et al., 2010). However, according to Quemada et
al., (2012), this concept is based on three fundamental dimensions:
sufficiency, continuity, and affordability. Sufficiency and continuity relate
to the need to ensure a stable and available supply capable of meeting
consumers' immediate needs. Affordability, on the other
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hand, pertains to long-term market dynamics and depends on
various factors such as technological advancements, the discovery of new energy
sources, and the balance between supply and demand. In addition, Stern (2002)
differentiates between short-term operational security, which seeks to prevent
unexpected supply disruptions, and long-term strategic security, shaped by
developments in supply and demand. Johnson (2005) emphasizes the importance of
resilience to exceptional circumstances in the short term, whereas long-term
security incorporates structural factors related to markets and investments.
Neorealism frames energy security as a strategic power struggle in which states
primarily aim to minimize their dependency. This perspective aligns with the
EU's prioritization of reducing its reliance on Russian gas (Cesnakas, 2010;
Ba°kan, 2024). The definition advanced by the EU encompasses the following:
cybersecurity, emergency oil stocks across MS, critical mineral access,
industrial production capacity for renewables, protection of critical
infrastructures, adequate electricity supply, security of gas supplies, and
sufficient gas storage capacities (Worl Energy Council, 2022).
b) Energy security and power
Contemporary theories in international relations focus on
security but tend to downplay the role of power in energy-related issues
(Kilinç-Pala, 2021). Authors from the realist school consider energy
security to be inherently linked to power and the balance between independence
and interdependence. This perspective helps explain why states seek to secure
critical resources (like energy) in order to maximize their survival and
influence. With structural neorealism, Waltz (1979) argues that energy,
especially exports, acts as a shield against external threats: by increasing
others' dependence, Russia strengthens its own security. Energy is viewed as a
political tool for asserting national dominance, ensuring protection, and
responding to threats (such as through sanctions). It thus becomes a strategic
lever in a geopolitical game, that is, a soft power tool, defined by Nye (1990)
as the ability to wield influence through attraction rather than coercion.
Russia has used its natural resources to keep Europe in a state of dependence
(Ba°kan, 2024; Dhaka, 2023).
c) Interdependency and Cooperation
According to Keohane and Nye (1977), the theory of complex
interdependence explains that even rivals can be bound by shared economic
interests. This interdependence contributes to
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reducing geopolitical tensions and fostering cooperation. In
this context, the control of energy flows becomes a mean of exercising
political influence through dependence and persuasion, without resorting to
military force or coercion. However, challenges to the exercise of soft power
arise from ongoing efforts in energy diversification and the green transition,
which undermine traditional leverage (Ba°kan, 2024).
This perspective aligns with the neoliberal discourse, which
argues that economic cooperation persists despite political tensions (McGrath,
2016; Wilson, 2019). Energy interdependence generates relative stability, and
multilateral commitments portray the energy sector as a vector of both economic
and political resilience (Ba°kan, 2024). Within this framework, the creation of
organizations like ITER, a program of international cooperation in fusion
energy research and development, illustrates how countries can come together to
address a common challenge (ITER, n.d.). However, this type of cooperation is
not without tension, particularly between Russia and the West, leading to
delays and renewed doubts about Russia's participation. In this regard,
cooperation has been weakened by European and American sanctions linked to the
conflict in Ukraine (Bentsen et al., 2014).
d) Securitization and Constructivism
More recently, scholars adopting a constructivist perspective
have expanded the analysis of energy-related decision-making by arguing that
such decisions are not solely driven by material factors (like geography or
economy), but also shaped by social constructs, identities, norms, and
perceptions (McGrath, 2016). As Wilson (2019) points out, framing energy issues
as existential threats often leads states to implement nationalist and
protectionist policies, thereby fueling international tensions and increasing
the risk of resource-related conflicts. This process, named securitization,
highlights that energy decisions are not merely determined by material or
geographical factors but are also deeply influenced by social perceptions and
the ideological frameworks within which states operate.
Similarly, Marusyk (2019) underlines that the energy
relationship between the EU and Russia is shaped by configurations of
identities, norms, and interests that go beyond pure economic reasoning.
Mitrova and Melnikov (2019) have shown that the discourse surrounding the
energy transition itself constitutes an arena of ideological confrontation,
where mutual perceptions and normative battles largely define strategic
orientations. In this light, the EU's efforts to diversify
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its energy sources and reduce its dependence on Russian gas
are driven not only by material imperatives but also by ideational dynamics,
where political narratives, identity representations, and threat perceptions
play a central role (Siddi, 2023).
2) Energy Transition at the EU Level a)
Energy Transformation Measure
In the context of climate change, energy transformation refers
to the various actions aimed at reducing greenhouse gas emissions, so the
process of shifting from fossil fuel to renewable energies (Ellabban et al.,
2014; Rybak & Manowska, 2023). To assess the effectiveness of this
transformation, the literature presents several quantitative tools. Firstly,
the Energy Transition Index (ETI), developed by the World Economic Forum in
2018, evaluates the progress made by countries in transforming their energy
systems. It is based on the idea that energy transition must not only support
economic growth and social development but also strike a balance between three
key pillars: (1) promoting economic development, (2) ensuring secure and
reliable access to energy for all, and (3) preserving the environment. The ETI
is structured around two areas of analysis: the current performance of a
country's energy system, and on the country's readiness and capacity to
transition (WEF et al., 2023). It measures both the present state of energy
systems and how well-positioned countries are to meet future challenges linked
to energy transition (Rybak & Manowska, 2023). In 2025, global ETI improved
by 1.1%, the energy system improved by 1.2%, but the report revealed that the
transition improved more slowly than the 10-year average (Ashraf et al.,
2025).
Secondly, the World Energy Trilemma Index (WETI), published
annually by the World Energy Council, evaluates the performance of 127
countries in managing the balance among three objectives: providing reliable
energy (energy security), ensuring universal access (energy equity), and
minimizing environmental impact (WEC, 2024). The report shows that Denmark and
Sweden rank first, France is fifth, Germany sixth, and Spain tenth (Worl Energy
Council, 2022). The WETI relies on both national and international data. It
thus is as a valuable resource for governments, experts, and researchers to
benchmark performance, identify best practices, and adjust energy policies for
greater sustainability. However, these indices do not take into account the
role of energy imports, an important gap especially in the context of the EU's
energy dependency (Rybak & Manowska, 2023).
b) 10
EU Sanctions on Russian Energy
In response to the invasion of Ukraine, the EU's energy
strategy shifted from energy interdependence to energy independence (LaBelle,
2024). Gradually, the EU imposed sanctions on the Russian energy sector,
starting with coal, followed by oil and gas. These sanctions faced strong
opposition from several MS, which argued that Russian oil and gas imports were
their only viable option making unanimity among EU countries the Union's main
challenge (Barigazzi & Kijewski, 2022). In order to preserve cohesion, the
European Commission called for a collective effort to reduce gas consumption
during the winter of 2022-2023, prioritizing support for MS in difficulty
(European Commission, 2022a; Council of the EU, 2023). Through these sanctions,
the EU aimed to weaken the Russian economy and thereby undermine its military
actions in Ukraine (Maruiak, 2024).
Consequently, a radical shift in energy flows has occurred:
in 2020, the EU depended on Russian gas for 40% of its supply, which had
dropped to less than 10% by January 2023. Meanwhile, Europe previously used 60%
of Russia's export capacity, saw its pipeline imports fall by 80% in February
2023 (IEAa, n.d). Consequently, the EU turned to new LGN providers, notably the
US and Qatar (Lambert et al., 2022).
c) Green Transition and Sustainability Framework
Given these disruptions, the EU identified an opportunity to
accelerate its energy transition by promoting long-term strategies, by
increasing investments in renewable energies: solar and wind power, and
hydrogen (LaBelle, 2024; Maruiak, 2024). Surely, the conflict in Ukraine
highlighted the EU's challenge of balancing Green Deal goals with energy
security. The literature on green transition raises questions about the EU's
capacity to align its energy diversification policies with its climate
objectives because Russia's invasion of Ukraine refocused political priorities
around energy security, to the detriment of environmental and social ambitions
(Kuzemko et al., 2022).
In this context, the Commission launched REPowerEU in May 2022
to reduce gas consumption by 18% and increase renewables to at least 42.5% by
2030, while also raising investments in storage, hydrogen, and interconnections
of EU electricity networks (Energy, n.d., Commission Européenne, n.d.).
This initiative is structured around the energy trilemma, theorized by
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Kuzemko et al. (2022), which now guide Europe's energy
strategy around three core pillars: diversification of energy sources,
development of renewable energy, and improved energy efficiency. Gitelman et
al. (2023) operationalize this framework by proposing a detailed typology of
diversification forms at the European level: (1) technological diversification,
or the expansion of the energy mix; (2) institutional diversification,
including the adaptation of regulations and governance models; and (3)
integrated management of energy planning. They advocate for a systemic
approach, framing diversification not merely as a response to crises but as a
strategic lever for sustainable transformation.
Finally, the debates surrounding nuclear energy have regained
interest in the literature. The discourse was previously dominated by a
technical approach promoting nuclear as a controllable and low-carbon energy
source highlighting innovations (Omar et al., 2022). Recent research has
adopted a more holistic perspective with a greater emphasis on energy policy,
security, climate change, and long-term sustainability (Fernández-Arias
et al., 2024).
d) Energy Governance and Policy Networks
To mitigate its vulnerability, the EU has diversified its
suppliers, notably by increasing pipeline imports from Azerbaijan, Algeria or
the US (Russell & EPRS, 2020). According to Kuzemko et al. (2025),
understanding the ongoing global energy system transformation requires more
than a mere technical rebalancing, but must be viewed as a dynamic, open-ended,
and conflict-laden process. They identified three dimensions shaping
contemporary governance: material infrastructures, spatial organisation, and
the political tensions that arise around energy choices where actors,
interests, and conflicts confront one another. Their approach goes beyond
traditional state-centric logics, integrating broader global realignments, such
as North-South tensions, debates surrounding fossil gas as a «transition
fuel,» and the rise of new non-state actors. In the same vein, Miík
(2022) argues that the 2021-2022 crisis exposed the EU's weak external energy
coordination, calling for more integrated, multi-level governance to align
energy security, decarbonization, and external partnerships. Moreover, Goldthau
and Sitter (2020) distinguish between International Political Economy, which
explains the fragmentation and power asymmetries in global energy regimes, and
Global Public Policy, which analyzes the tools used to shape new forms of
energy governance. They argue for moving beyond binary oppositions between
liberal, market-based and realist, security-driven approaches to develop hybrid
strategies suited to today's energy challenges.
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e) Critical Political Economy
Despite the measures undertaken, the EU must contend with the
economic dimensions of the crisis. It has introduced support mechanisms such as
windfall taxes on energy companies and financial assistance for vulnerable
households (Kuzemko et al., 2022). National initiatives within the Union,
including efforts to cap gas and electricity prices, illustrate the diversity
of approaches in the absence of a coherent energy rationing system (European
Commission, n.d.; Kuzemko et al., 2022). Theories of critical political economy
offer relevant insights into why energy diversification trajectories often defy
purely institutional or technical explanations. According to Goldthau and
Sitter (2021), current institutional structures and dominant interests, whether
state or private, contribute to a fragmented, incomplete and deeply unequal
energy governance system. Their conceptual framework first reflects the
influence of powerful companies and dominant states in shaping energy regimes
to serve strategic interests, and then raises questions about why global
regimes continue to fail to be effectively inclusive or efficient.
However, the energy transition is neither a linear nor
consensual process. Rather, it is shaped by a balance of tensions between
proponents of fossil gas and advocates of a rapid shift toward renewables.
These tensions also stem from institutional resistance, technological access
asymmetries, and North-South dynamics (Kuzemko et al., 2025). Al-Saidi (2023)
offers an original perspective on energy relations between Europe and the
Middle East, approaching them through the lens of international political
economy. He criticizes the EU's overly short-term vision and calls for
longer-term, more balanced cooperation strategies, taking into account internal
dynamics of supplier countries, such as reforms, political stability, and
infrastructure security. In his view, Euro-Mediterranean energy integration
represents a major geoeconomics lever, though it remains constrained by issues
of trust, mutual dependence, and fairness.
3) Member States Level: Implementation and
Differentiation a) Persistent Divisions in Decision-Making
The energy crisis triggered by the war in Ukraine has divided
MS with divergent national interests regarding the development and
implementation of a common energy policy. For instance, Hungary exercised its
veto, then the «constructive abstention» to express opposition to
sanctions against Russia (Maruiak, 2024). Such divergences have weakened the
EU
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cohesion and solidarity, exposing the institutional
framework's limitations in tackling energy security challenges (Miík
& Nosko, 2023). The debate over strengthening decision-making integration
through qualified majority voting is lively in the energy domain (Ondarza &
Stürzer, 2024). Although this reform could contribute to collective energy
security, it faces resistance because some MS fear to lose national autonomy
(Miík & Nosko, 2023).
b) The Evolution of the Energy Mix
The energy transition within the EU is advancing, but unevenly
across MS, which are moving at different paces (ACER, 2025). The reports
highlighted that coal, historically central in some countries such as Germany
and Poland, is gradually being replaced by wind power, solar energy, biomass,
and hydropower. Several examples stand out, including strong growth in offshore
wind energy in Denmark and the Netherlands, as well as significant solar energy
expansion in Spain and Germany. Moreover, in mountainous or forested countries,
biomass and hydropower make an important contribution (EEA, 2023; Rybak &
Manowska, 2023).
In 2022, Brodny and Tutak analyzed the similarities among EU
Member States in terms of sustainable energy development using indicators such
as energy consumption per capita, energy productivity, renewable energy share,
greenhouse gas (GHG) emissions, and dependence on energy imports. They
identified four clusters: (1) Denmark, Finland, and Sweden, characterized by
high per capita energy consumption and Total Primary Energy Supply available in
a country (TPES); low energy import dependence, high energy productivity, and
low GHG emissions. Then, (2) fifteen countries with moderate consistency, lower
energy consumption and productivity than Cluster 1, lower renewable shares,
higher GHG emissions, and medium dependence on imports; (3) Poland, Czechia,
and Estonia, showing considerable diversity, low import dependence and thus
greater autonomy, average energy productivity, but high per capita GHG
emissions due to coal (Poland, Czechia). Finally, (4) Belgium, Germany,
Ireland, Luxembourg, Netherlands, and Austria, marked by high per capita energy
consumption, TPES similar to Cluster 1, moderate renewable shares, high import
dependence, energy productivity, and GHG emissions (Germany, Ireland). This
classification highlights the differentiated energy profiles and challenges of
EU countries in achieving sustainable energy development (Brodny & Tutak,
2024).
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Weiner (2022) points out that Central and Eastern European
countries (CEEC), historically highly dependent on Russian gas, must develop
greater contractual flexibility and further integrate their energy markets to
strengthen their energy security. Meanwhile, the major Western MS have adopted
differentiated energy diversification strategies according to their national,
industrial, socio-economic priorities, renewable potential, and geopolitical
exposure (Tabagari, 2022). For instance, according to the International Energy
Agency (2020), nuclear energy is expected to contribute around 15% of the
emission reductions needed by 2050. However, in 2021, renewables accounted for
only 23% of the energy mix, still far below the 40% target set for 2030.
Despite ongoing debates over the costs and environmental impacts of nuclear
power, it remains central to France's energy strategy (Pata & Samour,
2022).
The literature presents a set of indicators used to measure
the energy transition at the MS level. Among these, the %RES indicator
evaluates progress in the energy transition by measuring the share of renewable
energies (solar, wind, geothermal, or biomass) in total energy consumption
(Kang et al., 2020). Between 2013 and 2022, most MS recorded an increase; for
example, Germany's share rose from 13.76% to 20.80%, while Estonia's increased
from 25.36% to 38.47%. Furthermore, dependence on energy imports has also
evolved. In Germany, for instance, it increased by approximately 6%, whereas in
Estonia it decreased by 8% during the 2013-2022 period. These indicators
reflect disparities that correspond to the varying capacities of MS to
reconcile energy transition with supply security (Rybak & Manowska,
2023).
4) Gaps in the Literature
While quantitative indicators are rich in information, there
is currently a lack of comparative data on the evolution of energy mixes across
EU Member States since the 2022 invasion of Ukraine. To address this gap, I
empirically analyze the cases of Spain, France, and Germany, highlighting how
recent geopolitical tensions differently influence national energy
diversification strategies. I will also cross-reference the technical dimension
of the energy transition with security challenges, which are too often treated
separately in the literature. By integrating political discourse, national
perceptions, and identity narratives, I will attempt to demonstrate their
structuring role in energy decisions. Finally, drawing on a qualitative method,
I aim to access the internal logics of action and tensions that escape purely
macro or quantitative approaches, while incorporating the often-underestimated
role of sub-state actors and energy communities in the concrete implementation
of European policies.
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