Russia and the European Union are substantially linked by trade in energy resources. Katja Bruisch and Benjamin Beuerle argue that these links have put European leaders, who are ostensibly committed to decarbonization, in the difficult position of backtracking on their goals to minimize energy insecurity and economic chaos--a position they could have mitigated or even avoided by more decisive action on fossil fuels. Russia’s brutal, largely oil- and gas-financed invasion of Ukraine brings home in the darkest of ways the dangers of basing international relations, institutions, economies, and lifestyles on fossil fuels.