The United States's crushing victory in the Spanish-American War greatly enhanced its status as a world power. At this time, the United States was already the world's richest and most industrially-advanced nation. But victory over Spain added military prowess to America's growing list of strengths.
Traditionally, American governments had fought shy of engaging too directly in foreign affairs. Ever since George Washington's famous "Farewell Address," with its warning of "foreign entanglements," successive administrations had shown a marked reluctance for the United States to take on a significant role on the international stage. But the easy victory of the Spanish-American War changed all that. From now on, the United States would unequivocally be an international power, ready and willing to use military force anywhere in the world to protect its strategic interests.