The US spends far more on its military than any other country (but not when compared to GDP). In 2015 America spent about $600 billion on U.S. defense spending.
Political Science is the science of politics, or the science of the nation-state. It is the art of diplomacy, the study of ideas, ideologies, and influence, the science of strategy, economics, and rhetoric, and more. Perhaps political science is best summed up by Aristotle in his discussing of man’s role in creating the ideal nation-city-state:
“Political science aims at what is the highest of all goods achievable by action…. though it is worth while to attain the end [AKA happiness/arete/”the greatest good”/”the highest good”] merely for one man, it is finer and more godlike to attain it for a nation or for city-states. These, then, are the ends at which our inquiry aims, since it is political science, in one sense of that term.” – Aristotle on the meaning of life, virtue, morals, ethics, and the city-state, Nicomachean Ethics 350 BC