The new century would transform American grand strategy in different but comparable ways. By a wide margin, the 20th century would prove to be the most catastrophic in history. The Spanish-American War, while revealing many shortcomings in organization and supply for the land forces, showcased a powerful and competent Navy with global reach and made the United States an imperial power with newly won possessions in the Caribbean (Puerto Rico) and the Pacific (the Philippines and Guam). America had now moved decisively onto the world stage. In the second decade of the century, it became clear that war loomed in Europe, as armies assumed massive proportions, professional general staffs perfected the machinery of mobilization, and industrialization and advancing technology equipped armies and navies for large-scale, protracted war. The United States, preoccupied with colonial concerns in the Philippines and protected by an impressive fleet and the Atlantic and Pacific oceans, genuinely pursued a neutrality that would eventually founder on two key strategic dilemmas: the protection of trade and markets, and the potential rise of a hostile power in control of the European landmass. American pride was certainly touched by unrestricted submarine warfare, but what could not be borne was the isolation of U.S. commerce from European markets or the prospect of German control of all of Europe’s economic and demographic resources