Recent debates in Japan over dispatching Japanese Maritime Self Defense Force as part of coalition activities in the Indian Ocean has brought to fore the difficult relationship between domestic politics and participation in multilateral operations. Meanwhile, in the United States, many observers criticize the limited contribution of some European countries in multilateral military operations and the restrictions placed on their military forces, the so-called “national caveats.” Most critiques point out that multilateral military operations are difficult due to two gaps: “capability gap (size, equipment, technology)” and “willingness gap (casualty aversion, sense of urgency)” between the United States and coalition countries and amongst the coalition countries. However, there is another important “gap” that has been overlooked: all countries have different rules regarding when and how to send troops abroad. In other words, “institutional gap” or different domestic systems of accountability for use of force affect what militaries can do, and how militaries can cooperate with one another. In this project, I seek to make an academic contribution to these debates by asking the following questions: What are different rules regarding sending troops abroad in coalition countries? Why do some countries choose restrict forms of oversight while others give the military more discretion? How do these differences affect the effectiveness of coalition operations? Does increased military to military interaction lead to less or more restrictions by national governments? And most importantly, how can we balance domestic accountability and international effectiveness in multinational military operations? To answer these questions, I examine the relationship between domestic level systems of accountability and international effectiveness by looking at the relationship from two directions: (1) how domestic civil-military relations affect the level of military discretion, and (2) how the interaction between the militaries affect domestic civil-military relations; especially whether it creates competitive pressure for more military discretion and less domestic oversight. These two directions contribute to three major issues in the field of political science, (1)civil-military relations, (2)domestic politics and international cooperation, and (3)the debate over the “democratic deficit.” There are two main components to this project, (1) creation of a data base, and (2) fieldwork at US Central Command (CENTCOM) and US Pacific Command (PACOM). First, I will construct a data base on national rules regarding the use of force. Ideally, I should cover all democratic countries, but for practical purposes I will only include countries represented at USCENTCOM and/or USPACOM. Second, I will conduct interviews among military representatives of coalition countries stationed at the US Central Command Headquarters (CENTCOM), and US Pacific Command Headquarters (PACOM). Both locations offer a unique opportunity to conduct interviews with representatives from numerous countries without having to visit each country. Also, through these interviews, I will able to understand how the realities of coalition operations, and how countries coordinate with the United States and with one another on a daily basis. Third, based on the findings from data collection and interviews results, I will explore ways in which we can balance domestic accountability and international effectiveness in multilateral military operations.