Can Montenegro, Saint Kitts and Nevis be put in the same category of ‘micro-States’ ? In international law, one refers to small States, not to micro-States. Can one offer a classification that would differentiate ‘micro-States’ from ‘mini-States’ within the category of small States ? Small States are congenitally haunted by their fear of disappearance, which sets them apart from their counterparts. Hence, several idiosyncrasies ensue: geopolitics of survival, taking root in self-determination, the will to safeguard their heritage and culture to make up for a strong feeling of vulnerability, and, finally, a strong leaning towards regional cooperation. Notwithstanding those common features of small States, the ‘mini-State’ would differ from the ‘micro-State’ on the five following criteria : the idea of nation, the mutation in the right to self-determination since the fall of the Communist block, the encounter with the political, their geographic position and defence capacities.