International criminal courts and tribunals regularly face difficulties in obtaining cooperation from States, a stumbling block that hinders the process of bringing criminals to justice and trying them before a court of law. In doing so, States can be held accountable under the rules of state responsibility. This possibility was raised in key decisions and scholarly texts on the issue. This paper seeks to expand the discussion on the matter and analyze the responsibility of States for their failure to cooperate with international courts. Additionally, this paper suggests amendments to the ICC Rome Statute to strengthen the judicial assistance regime, considering that this court is designed to become the permanent court dealing with war crimes and crimes against humanity and that a review of the Statute is to take place in May or June 2010.