Will future battlegrounds be on water .... I would have to say 'yes and no'. For countries in the Far East .... the focus will be on developing both naval and air forces for future conflicts. For regions like Africa, the Middle East, etc. .... the ground battlefield will be the defining one.....soon....
Europe is a landscape; East Asia a seascape. Therein lies a crucial difference between the 20th and 21st centuries. The most contested areas of the globe in the last century lay on dry land in Europe, particularly in the flat expanse that rendered the eastern and western borders of Germany artificial and exposed to the inexorable march of armies. But over the span of the decades, the demographic and economic axis of the Earth has shifted measurably to the opposite end of Eurasia, where the spaces between major population centers are overwhelmingly maritime.
Military engagements on land and at sea are vastly different, with major implications for the grand strategies needed to win -- or avoid -- them. Those on land enmesh civilian populations, in effect making human rights a signal element of war studies. Those at sea approach conflict as a clinical and technocratic affair, in effect reducing war to math, in marked contrast with the intellectual battles that helped define previous conflicts.
World War II was a moral struggle against fascism, the ideology responsible for the murder of tens of millions of noncombatants. The Cold War was a moral struggle against communism, an equally oppressive ideology by which the vast territories captured by the Red Army were ruled. The immediate post-Cold War period became a moral struggle against genocide in the Balkans and Central Africa, two places where ground warfare and crimes against humanity could not be separated. More recently, a moral struggle against radical Islam has drawn the United States deep into the mountainous confines of Afghanistan, where the humane treatment of millions of civilians is critical to the war's success. In all these efforts, war and foreign policy have become subjects not only for soldiers and diplomats, but for humanists and intellectuals. Indeed, counterinsurgency represents a culmination of sorts of the union between uniformed officers and human rights experts. This is the upshot of ground war evolving into total war in the modern age.
East Asia, or more precisely the Western Pacific, which is quickly becoming the world's new center of naval activity, presages a fundamentally different dynamic. It will likely produce relatively few moral dilemmas of the kind we have been used to in the 20th and early 21st centuries, with the remote possibility of land warfare on the Korean Peninsula as the striking exception. The Western Pacific will return military affairs to the narrow realm of defense experts. This is not merely because we are dealing with a naval realm, in which civilians are not present. It is also because of the nature of the states themselves in East Asia, which, like China, may be strongly authoritarian but in most cases are not tyrannical or deeply inhumane.
The struggle for primacy in the Western Pacific will not necessarily involve combat; much of what takes place will happen quietly and over the horizon in blank sea space, at a glacial tempo befitting the slow, steady accommodation to superior economic and military power that states have made throughout history. War is far from inevitable even if competition is a given. And if China and the United States manage the coming hand-off successfully, Asia, and the world, will be a more secure, prosperous place. What could be more moral than that? Remember: It is realism in the service of the national interest -- whose goal is the avoidance of war -- that has saved lives over the span of history far more than humanitarian interventionism.