Military operations increasingly require cooperation between agencies within the same nation, but also collaboration with security and military organizations internationally. Throughout history multinational military cooperation has often been an appropriate way to conduct major operations; national manpower and material resources are generally insufficient to address the demands of missions worldwide. The desire to optimize the use of scarce research and development and investment capabilities, the need for international legitimacy and political support, and the fact that today’s risks transcend national borders, have rendered multinational cooperation in the security domain unavoidable. With joint operations comes the requirement for multi-partner- and multinational information sharing. However, information sharing has both advantages and costs, and is subject to both enabling factors as well as barriers. This paper reflects on theories, both classical and current, as well as empirical case studies, to examine the pros and cons of multinational information sharing, and the factors that conduce or interfere with the transmission and the receipt of intelligence. The importance of a holistic approach and of learning lessons learned are two key lessons gleaned from the analysis, along with an emphasis on developing both the organizational and the interpersonal enablers of information sharing.