Anti-trust issues increasingly reach beyond national borders. This paper addresses the question whether such issues can reasonably be solved by an extraterritorial application of national competition law or whether they call for an international competition policy of its own. The analysis is based upon 20 case studies which are examined with regard to the suitability of the effects doctrine and the principles of comity as conflict resolution mechanisms. The case studies demonstrate that conflicts in international anti-trust are more likely to arise where national competition laws differ from each other or where national authorities are pursuing selfish national policy objectives.