Which term explains a key foundational value behind U. S. involvement in the Spanish-American War?

The Spanish-American War was a military conflict between the United States and the Kingdom of Spain from April 23 to August 12, 1898. It ended with the United States taking possession of Cuba and Puerto Rico in the Caribbean, and Guam and the Philippines in the Pacific Ocean.

For the United States, this war marks the first successful confrontation in the context of its new, far-reaching Manifest Destiny policy and marks the transformation of the Monroe doctrine from a primarily defensive to an expansive strategy as an openly imperialist colonial power.

answer; beware of exaggerated claims without supporting evidence;