This paper addresses one of the intricacies of international competition law enforcement, namely the diversification of legal instruments used for bilateral cooperation. To name only a few: why are memorandums of understanding, dedicated competition cooperation agreements, competition law provisions in free trade agreements, and policy dialogues used in parallel to attain bilateral cooperation on competition law enforcement? What is the added legal value of each instrument? Is their added value to be found in political considerations? The argument put forward in this paper is that a parallel can be drawn between the internal and external functions of competition law. As competition law is not a goal as such within the EU, but in general serves the optimal functioning of the Single Market, the function of international cooperation on competition law matters is not solely to be found in competition considerations, but serves other goals as well. Therefore, the fact that a number of different objectives are pursued may explain the use of several distinct instruments for cooperation on competition law issues
