Much has been made of the US' recent withdrawal from leadership in multilateral institutions. This is often contrasted with the approach of the European Union. The Treaties commit the EU to seek solutions to international problems through multilateral means, and the EU has sought to influence the development of international law via multilateral institutions. Yet in recent years, many of the EU’s policies have been criticized for being ‘unilateral’, or even breaching international law. The approach of the Court of Justice of the European Union to international law has been less open to international law. In areas such as climate change mitigation, and human rights protection, the EU’s unilateral approach often stems, not from a disengagement with multilateralism, but from an inability to make progress through multilateral institutions. This contribution discusses whether the EU may be undermining global institutions and respect for international law through its action.