The military superiority thesis contends that the key to the ascendancy of western Europe as the world's predominant region was its edge in military technology. Thanks to intensive regional warfare and a series of military revolutions, military superiority enabled Europeans to subordinate the rest of the world between 1500 and 1900. At best, this interpretation gives too much explanatory weight to military technology. Other factors that were equally if not more important were the variable vulnerabilities of Afro-Eurasian and American targets of expansion, the need for and availability of allies, and the evolution of a global political economy in ways that favored increasing European predominance. As explored in five cases, ranging from Mexico and Peru to southeast Asia in the fifteenth through eighteenth centuries, none of these factors worked entirely independently of the others. Rather, they interacted to promote the ascendancy of some Europeans for a period of time. Military superiority, and especially naval superiority, may have been most important for facilitating first the arrival and then the survival of Portuguese, Dutch, and English forces along the maritime fringe of Afro-Eurasia.