<P>This is the fourth, revised and updated, edition of Geoffrey Till''s <I>Seapower: A Guide for the Twenty-first Century</I>.</P><P></P><P>The rise of the Chinese and other Asian navies, worsening quarrels over maritime jurisdiction and the United States¿ maritime pivot towards the Asia-Pacific region reminds us that the sea has always been central to human development as a source of resources, and as a means of transportation, information-exchange and strategic dominion. It has provided the basis for mankind''s prosperity and security, and this is even more true in the early twenty-first century, with the emergence of an increasingly globalised world trading system. Navies have always provided a way of policing, and sometimes exploiting, the system. In contemporary conditions, navies, and other forms of maritime power, are having to adapt, in order to exert the maximum power ashore in the company of others and to expand the range of their interests, activities and responsibiliti