Functional independence of international institutions is a sine qua non to their effective operation. Current international law reveals that international organizations have a legal capacity and certain privileges and immunities bestowed upon them by their member states to ensure their independence and that of their staffs. One vital component of functional independence is the freedom of travel for all members of the international staff. In examining the features of freedom of travel necessary for international organizations to discharge their responsibilities effectively, C. W. Jenks wrote:
The freedom of movement which is necessary comprises more than the absence of any special restrictions; it includes the usual facilities for official travel, such as diplomatic or other special visas, priorities where these are necessary, exemption from immigration regulations and formalities, and similar measures; taken cumulatively these facilities involve a considerable saving of time and energy and are therefore an important element in securing the expeditious and unhindered travel necessary to the prompt discharge of international responsibilities.