In the context of the follow-up work arising from the World Summit on the Information Society (WSIS), this paper attempts to answer the questions: Why should librarians and information workers be involved in international advocacy? And what are the international issues with which librarians should concern themselves? Special attention is paid to the role of IFLA, as the main international body representing the interests of librarians, and to the eleven WSIS "action lines" set out in the 2003 Geneva Plan of action, along which much of the current follow-up work is aligned. As a framework for our answers, the concept of the Knowledge Society, and more specifically four criteria for a Knowledge Society: ICT infrastructure, information content, human intellectual capacity, and physical delivery infrastructure, is used. A brief discussion of these and some comments on the WSIS process precede a broad outline of the international issues facing library and information professionals.