Coming Anarchy features a map of Germany's oil imports. Independent research by me shows pretty much a similar pattern for most of western and central Europe with France and some others receiving some Iranian oil.
Much of Europe and especially eastern Europe is dependent on oil from Russia. As the Russians have shown via there power games with their supply pipe lines, that is a tenuous relationship. This gives Putin an even stronger hand when it comes to negotiating deals with the European Union.
Improved relations with Libya will also allow that country to increase its oil output even more. Libya has been taking out ads in international newspapers stating how it is open for business.
Iran has issues with its oil exporting. The lack of infrastructure and some odd deals has caused the regime to ration gas for its citizens. The president of Iran has once again proven himself incapable of sound economic policy.
The globalized first world needs energy to survive and grow. The deals these countries make with others continues to play a massive role in the geopolitical situation and will into the future.