Topic: What's the point of having a large modern army?
I don't quite get it, on a strategic level, why the US has a large modern army. So perhaps people in the military can explain this to me.
My thought is this. An army serves two purposes: to eliminate an enemy army and occupy a territory. The US army can defeat an enemy army pretty well, but so can our air force with much less expense. For occupying a territory, it isn't so good at. Sure a single US soldier can do more than a conscripted and less equipped one, but the equipment and upkeep is very expensive. Powerful armies today may employ well equipped and well trained soldiers, but having a large mass of them is impractically expensive. The US' army is large, but not nearly the size of the conscripted armies of World War I or World War II, where 20 million men may have been fielded by a single nation at any time. This small size, expensive army makes occupying several countries impractical, and reduces the ability to project military force elsewhere. This is why the US war in Afghanistan and Iraq is very expensive and there were complaints of our forces being spread too thin, whereas in the days of conscripted soldiers occupation would have been easier and less expensive.
So this leaves us with the fact that a powerful air force can eliminate an army from the skies just fine, and it's inefficient to employ such heavy infantry to occupy a country. Here's an analogy. Nobody would deny that knights were awesome soldiers back in the medieval period, but who in their right mind would have used them to occupy a territory? Sure knights could be better than your average peasant foot soldier at occupation, but using the knights for this purpose would be inefficient.
I think it makes more sense for the US to downsize the army, which to me makes no sense that it is the largest branch of the US, and rely more on the air force and navy. In fact, we shouldn't be afraid to use the air force in a ruthless manner against scum who dare challenge our empire. Level cities if we need to, that always works effectively. Our army should be primarily used to occupy strategic locations and for tactical missions, not for main combat or occupation. Furthermore, by accomplishing our political objectives using our naval and air power, we can eliminate our enemies more efficiently and with less cost, and enjoy more mobility. Our current strategy of using our army to the extent we do has opened a power vacuum by entangling our forces in two countries, and therefore reducing our ability to project force around the world. With a naval and air power centered strategy, we can get in and out and go somewhere else very quickly. Lastly, it's a lot easier to maintain naval and air supremacy than it is ground supremacy (e.g. you're going to know it if someone is building a fleet of aircraft carriers). Moreover, today naval and air supremacy can cancel out ground supremacy. So why the US relies so heavily on ground supremacy confounds me. If you want to occupy a country, it's a lot cheaper to use mercenaries and buy off dictators.
So those are my thoughts. Now I would like to invite people with military experience and a lot more knowledge on the matter to give their thoughts on my reasoning.