Short answers, pulled from the story.
Military globalization is defined by David Held as "the process which embodies the growing extensity and intensity of military relations among the political units of the world-system." Robert Keohane and Joseph Nye describe it as "long-distance networks of interdependence in which force, and the threat or promise of force, are employed."
David Held, and the pair Robert Keohane and Joseph Nye, are the scholars most closely associated with defining military globalization. Held further divides the concept into three distinct phenomena, covering the war system, arms production and transfers, and the international regulation of force.
Accounts of when military globalization began differ. One view traces the process back to the Age of Discovery, when European colonial empires began conducting military operations on a global scale, while Robert Keohane dates it back at least to the conquests of Alexander the Great.
The First World War is described as the first global conflict in world history, arising from imperial rivalry among European colonial empires that had been conducting military operations on a global scale since the Age of Discovery.
David Held divides military globalization into three parts: the globalization of the war system, covering 'geopolitical order, great power rivalry, conflict and security relations'; the global system of arms production and transfers, reflected in the global arms dynamics; and the geo-governance of violence, described as 'the formal and informal international regulation of the acquisition, deployment and use of military force.'
As of 2025, only one book has been devoted completely and explicitly to military globalization, despite a large body of literature on globalization as a whole.