In most national systems, criminal liability arises when a person agrees to commit an ordinary crime, participates in the design of a criminal plan, or contributes to establishing the conditions necessary for its execution. The extension of the scope of criminal law at the national level to criminalize preparatory acts for ordinary crimes, regardless of whether the crime is subsequently completed or even initiated, has been used, to an important extent, to confront situations in which a group of persons engages in criminal conduct to achieve economic (e.g., trafficking of human beings, drugs, and weapons, or money laundering) or political (e.g., terrorism) goals. The question that then arises is why preparatory acts for the international crimes that come under the jurisdiction of international criminal tribunals and hybrid tribunals are not criminalized in international criminal law, for the most part. In addition to constituting the most egregious attack on the core values of international society, such acts are of a unique magnitude, have a collective nature, and take place in an organizational context.
