Outside Forces, Inside Change: How Russia and Trump Reshape European Integration Politics

This paper explains how two major outside events – Russia’s war against Ukraine and the second Trump presidency in the United States – are transforming the politics and study of European integration. Earlier research mostly focused on “inside” causes, such as economic interests, institutions, or public opinion within Europe. Today, outside shocks strongly shape what the European Union does, especially in foreign, security, and defense policy. We first show that this “outside-in” logic is not fully new. During the early Cold War and again in the 1970s, outside pressure also influenced European integration. However, the current situation is special because two major outside causes arrive at the same time. Russia is breaking the European security order, while the United States under Trump questions Europe’s trust in the transatlantic alliance. Together, they create strong pressure on the EU to react. These outside causes lead to new inside effects. The EU has agreed on unprecedented sanctions against Russia and gives Ukraine large financial, political, and military support. Member states are investing hundreds of billions of euros in defense and are discussing new forms of military cooperation. For the first time in EU history, leaders also debate nuclear deterrence. Options include a French nuclear umbrella for Europe, a possible future EU deterrent, or even national nuclear programs in countries like Poland. All options face problems of credibility, cost, and decision-making. We argue that European integration has now entered a phase of “existential politics.” Many decisions no longer follow long-term plans or internal goals, but come from urgent need. The EU reacts because it must, not because governments choose to deepen integration for positive reasons. This is especially true in security and defense, which were once the last areas of national control. The paper suggests a new framework to study this shift, based on inside/outside causes and inside/outside effects. It shows that foreign policy, security, and nuclear issues are now central to understanding both Europe’s future and the changing world around it.