Global merger control enforcement has become more interventionist across Europe, the US, Middle East and Australia, with antitrust regulators increasingly inclined to scrutinize and challenge mergers. Against the backdrop of continuing international divergence and growing jurisdictional uncertainty, regulators are turning their attention to below-threshold mergers and novel theories of harm. The arrival of the FSR in the EU together with the increased global FDI scrutiny add a new layer of complexity to an already challenging landscape of dealmaking.