Competition and regulation are typically seen as alternative disciplining forces on market actors. On this view, the more competitive a market is, the less need there is for ex ante regulation of competition, and the competition law enforcement that occurs ex post is regarded as less information-intensive disciplining mechanisms. EU liberalization legislation in the network service industries, such as telecommunications, envisages that regulation will play a lesser role as competitive rivalry increases over time. In light of such a view of the division of regulatory labour, it may seem surprising that the interventions of competition enforcers both in the US and the EU have increasingly been characterized as regulatory in their goals and implementation techniques. The chapter argues that the transition to an effects-based competition policy with a focus on concrete case-based theories of harm has led competition decision-makers to implement problem-solving remedial techniques that blur the distinction between ex ante and ex post intervention by allowing for learning and remedial adjustment in the course of implementation. Both the modalities of learning between competition authorities that are part of the European Competition Network and the growing use of commitment-based remedies at EU and national level may be viewed through that analytical prism. Finally, it is argued that we should be slow to assimilate these techniques to regulation, as they may in fact offer the possibility for overcoming the limitations of both the legal and the technocratic paradigms of competition policy.