I'm listening to the American Peril podcast of Hardcore History by Dan Carlin and he keeps talking about how fascinated people were with war in America during this period of the late 1890's. My question is this is only 30 years or so after the Civil War, the most violent conflict in American history that left hundreds of thousands of people dead and huge swaths of the country destroyed. Surely there's still veterans alive who remember how awful it was and civilians as well. How is it that this idea that war was something noble be around? And, how is it, it became so popular?
Lodge and Roosevelt were both products of the Northeast and were young men during the American Civil War. This experience was formative in shaping their view that the Yankee-inspired conception of the United States' mission and place in the world was divinely ordained by its triumph over the rival vision espoused by the provincial and ignorant Southern Planter class and their more "common" cohorts in the Democratic party. People like Roosevelt and Lodge (and I think you can group Elihu Root and John Hay in with this cadre as well) conceived of the United States as a global commercial power, justified in its use of military force by the righteousness of its mission. The victory of their "side" in the most momentous conflict in American history illustrated the importance of the willingness to resort to armed conflict in order to fulfill a national destiny. There was subsequently a great amount of glory and nobility attached to participation in war (which partially explains Roosevelt's volunteering during the Spanish American War).
Like many who observed and studied the world at this time (Lodge was one of the first ever recipients of a history ph.d at Harvard), American imperialists found the useful and virtuous nature of war to be self-evident. Since the Napoleonic Wars' end in 1815, Europe had been in a long period of relative peace. The wars that were fought were brief and contained (e.g. the Wars of German Unification, The Crimean War) and never affected any great social or political cataclysm (as had been the case in the Napoleonic Wars). Military force was thus seen as a legitimate and justified means to pursue national interests. Because the United States had the superior system of governance and society, it was only natural to Imperialists like Roosevelt and Lodge that Americans should use the proven effective method of war. The destruction wrought by the Civil War was a unique and unrepeatable phenomenon to their minds because the irreconcilable sectional and ideological divide that caused it had been permanently extinguished.
It's also important to note that white Southern Democrats, the group that would take the most issue with the Civil War, were a politically marginalized class by this point. Since Lincoln, every president except Grover Cleveland had been a Republican and even he was a northerner. Republicans held congressional power for the majority of this period and their long epoch of political dominance emboldened more hawkish elements, like Lodge, to push their agenda and shape national opinion.
There was also a prevailing sense internationally that a strong military was necessary for a nation's survival, let alone its success. This was the era of Social Darwinism. Politically, this crystallized into the idea that nations were in competition with each other for land, resources, labor, and markets. The best way to ensure that the national interest was realized and protected was through a strong military, particularly a navy. This idea was most pervasively put forth in Alfred Thayer Mahan's The Influence of Sea Power Upon History which was read enthusiastically by Roosevelt and Lodge (and Kaiser Wilhelm II).
Sources:
Herring, George C. From Colony to Superpower: U.S. Foreign Relations since 1776. New York: Oxford University Press, 2008
MacMillan, Margaret. The War That Ended Peace: The Road to 1914. New York: Random House, 2013.
Widenor, William C. Henry Cabot Lodge and the Search for an American Foreign Policy. Berkeley: University of California Press, 1980.