This paper explores the legal issues surrounding the co-operation with international tribunals, taking into consideration the fact that successful implementation of the international tribunals and the tribunals of international character rely solely upon the full co-operation of third states with these same tribunals. It is precisely because the work of these tribunals relates to other states, that the co-operation of those states with these tribunals is essential both in investigative procedures and to secure successful prosecutions. Due to the fact that the Special Tribunal for Lebanon (STL) is the first tribunal of international character in the Middle East, this paper will concentrate on the co-operation of third States with the STL and its judicial governance concerning third states. It will take into consideration how the international legal obligations that have constructed the posture of the STL have impacted upon its judicial relationship as regards third states co-operation. While the Agreement between the United Nations (UN) and Lebanon provides a solid framework for co-operation between the STL and Lebanon, the Security Council Resolution 1757 (2007) is silent as regards the duty of third states to assist the Tribunal. As a result, the STL will be confronted with a variety of obstacles and problems in obtaining co-operation of third states-including Syria- which may seriously impede the functioning and effectiveness of the STL as a whole and undermine its legal capacity. The importance of Syrian co-operation with the STL does not just bear upon the functioning and effectiveness of the legal capacity of the STL; but rather any failure on the part Syrian co-operation could also have serious consequences for Syria itself. Conditional or limited co-operation would benefit Syria in several ways. It would protect Syria from being placed under any threats of the UN issuing resolutions under Chapter VII of the UN Charter to oblige all states to co-operate with the STL. Such resolutions could impact negatively upon Syria as a whole. Any negative impact upon Syria as a result of its failure to co-operate with the STL could include the possibility of the UN imposing economic sanctions or even the threat of interventional force, although the latter may be unlikely but nevertheless may still exist as a possible, albeit extreme, course of action to force Syria to co-operate. The importance of Lebanon to co-operate with the STL is also beneficial for Lebanon. Firstly, Lebanese co-operation will achieve the objective of the STL which is to enable and facilitate the full extent of justice to run its course. This is not just for the benefit of the victims and their families, but also to address and deter the political assassinations and trans-boundary terrorism which has affected Lebanon. Therefore, this article attempts to address the co-operation issues related to the tribunals. As the STL is the first tribunal in the Middle East, it will be this tribunal which will be the subject of detailed study in this paper. This paper will then conclude whether Syria is within its legal remit to choose whether to co-operate with the STL or not or whether it retains the right, as set out in its own Constitution, to try any potential suspects under Syrian law and within the Syrian judicial system.