This study aims at advancing theoretical understanding of the role of small island developing states (SIDS) in contemporary international relations (IR). It does this by examining their interaction between, participation in, and contribution to, IR within the framework of the UN. The literature on small states in IR was reviewed, in order to develop a conceptual framework for critiquing the small states paradigm, which is based on realist theory. This paradigm views the role of small states in IR as determined by inherent internal factors (physical size and capacity to act) and prescribes them as being insignificant and passive actors in IR. Contrary to the small states paradigm, a review of literature showed SIDS to be highly visible and proactive in IR in recent times. Thus, the research question the thesis pursued was: How can the small states paradigm in IR be strengthened to better explain the rising importance of the role of SIDS in contemporary IR? The literature review also suggested a proposition for testing empirical research: that external factors outside states are facilitative of the proactive and contributory behaviour of small states in IR. Two case studies of the role of SIDS in UN negotiations were selected to assess the extent to which they may have been influential on outcomes: Law of the Sea and Climate Change. The role SIDS played in the negotiations for each case was explored through analysis of relevant documents and interviews with diplomatic and resource persons from a selection of participating SIDS. Results strongly suggest that external factors are instrumental in facilitating proactive and influential behaviour of SIDS in these two UN negotiations. The key external factors numbered 18 and were grouped into the following dimensions: developments, events, trends, issues, circumstances and actors. These results call for revising the small states paradigm, so that it includes external factors as explanatory variables for the proactive and contributory behaviour of small states. Thus, external factors were added to the paradigm as open-sky dimensions which, unlike closed-ground dimensions (internal factors), are dynamic, flexible, optimistic and open elements (like the sky), and thus provide far wider potential or opportunities for small states in IR.