Phillip Bobbitt in the Daily Times makes an interesting but ultimately highly unsatisfying argument. He argues based upon a reading of Thucydides that there are such things as epochal wars- he gives other examples of such wars, the Hundred Years War between Britain and France, the Thirty Years War in Germany, and suggests that what makes them epochal is the way that a historian or historians unite them together in a construct, showing that all the wars depend upon the same reason. For Thucydides for example, Bobbit argues the Peloponesian war was a unity because it resulted from the unhealthy rivalry between the city states of Greece in the fifth century BC.
Bobbitt is right to point out to us that wars and periodisation within history are artifacts created by historians. They flow not from the essential nature of things but from the historian's ability to classify them- so that for example the Hundred Years war describes a period of alternating war and peace between England and France not a continuous war. The thirty years war though it does describe continuing warfare for thirty years, still includes wars between various states in which the actors came in and out of the minuet of conflict like dancers at a ball, everyone changing partners but the dance continuing. The same might be said to a degree of the First and Second world wars, there were discontinuities within the makeup of the coalitions on either side.
Essenses though are things that historians fly away from. Much of the historiography of our own time has been about the breaking up of large conflicts into pieces or the unification of previously disparate conflicts and periods. One can through understanding the Dutch position in the Thirty Years War, as Jonathan Scott has, elucidate the under currents of British civil war politics. John Morrill and Conrad Russell have forced us to see that the English Civil War was a war of three Kingdoms, not just a war confined to England. Other historians focus in and draw out the unique features say of the Somme to British culture. Historians continually move their microscope in and out, attempting to capture the place of a detail within a larger period. Periods are fluid, so Jonathan Israel moves the enlightenment's origins back to the 1650s even as Jonathan Clarke moves the end of the ancien regime in England forward to the 1850s.
Bobbit's epochal wars and his reliance on a single imagination to make them ends up losing what is so instructive about history which is its variety. Not merely a variety of subject studied, but also a variety of imaginations to study it. A variety of simularities across period noticed and variety of ways of defining human experience. History is about the knowledge of the particular, but to know the particular one must appreciate the general and always in the historian's mind there is a dialogue both between the details he knows and the wider picture he infers from his own research, and also between his own research, his own picture and that of others.
We should not fossilise our own attitudes too readily- history is a pilgrimage but the point of pilgrimage isn't arrival- its travelling.