Paul Kennedy es autor del clásico de las Relaciones Internacionales Auge y Caída de las Grandes Potencias.
A watershed is, by Webster’s definition, an aspect of physical geography: an area bounded by water parting and draining down a particular course. The water to the north of this divide runs in one direction, the water to the south of the divide runs the opposite way. But for centuries the term has also been used to describe a historical and political phenomenon: that is, when an array of existing human activities and circumstances pass, irrevocably, from one age to the next, across a great divide.
At the time, very few contemporaries sense that they have entered a new era, unless of course the world is coming out of a cataclysmic war, like the Napoleonic wars or World War II. But such abrupt historical transformations are not the focus of this article. My interest is in the slow buildup of forces for change, mainly invisible, almost always unpredictable, that sooner or later will turn one age into another.