This issue of Questions internationales, "Geopolitics of the Oceans", to which Alexandre Magnan contributed, highlights, with the help of specific examples, the unity of the international problems raised by fragmented maritime spaces and the universality of the principles that apply there.
Historically considered as an open space, the sea has been segmented over the years to the benefit of coastal states. Maritime spaces are now at the heart of globalisation and strategic competition between states for three main reasons: economic, demographic (65% of the world's population lives in port and coastal areas) and geopolitical (straits, canals and a number of islands are at stake to the point of causing tension between certain countries). However, the individual extensions of states leave the question of collective responsibility for maritime areas fallow. They remain largely subject to strategic and economic competition, of which the environment is the poor relation.