"A Study in Causation of the Mexican War" examines whether or not the Mexican-American War was an exercise of American Imperialism.

Webster's dictionary defines "war" as an open armed conflict between countries or between factions within the same country. It is a conflict often resulting in the death of many innocent civilians, the destruction of private property, and sometimes the unjust treatment of prisoners. Many would agree that war ought to be a last resort to settling a conflict, as was the case for James K. Polk in the Mexican-American war. Some have argued that the …

…neither desired nor provoked by the United States, who on the contrary, resorted to all means necessary to prevent it. Thus it is inappropriate to associate the Mexican war with American imperialism. As a final note, Polk himself had stated in a speech to Congress, "Mexico, in violation of solemn treaty stipulations and of every principle of justice recognized by civilized nations, commenced hostilities, and thus by her own act forced the war upon us."