"Closer to the center of European society, armed enterprise by one sovereign was sure to provoke a countereffort by rivals; and only rarely could a ruler conquer territories from which important tax income could be garnered. The success of the Spanish government in fashioning a vast empire in the Americas and its failure to maintain control over the Netherlands illustrate these facts very clearly. Spanish military effort in the New World paid off handsomely. Indeed it was the swelling flow of New World silver after the 1550s that made Philip think he could conduct war both in the Mediterranean against the Turks and in the north against the Dutch." -Source: William H. McNeill, historian, The Pursuit of Power: Technology, Armed Force, and Society since A. D. 1000, 1982 The conflict described in the excerpt is most similar to conflict in what other period?