War has always been a past time, a plaything really, of the rich and wealthy; engaged in to protect or expand their estates, which nowadays are their enterprises and empires. From medieval times to today, it's generally been peasants and paupers who man the armies that protect the assets, estates and property of the rich and wealthy. When did you ever hear of peasants or laborers raising a standing army of their own, or staffing it with members of the rich/wealthy class?
So, in our time, it makes sense for the federal government to be the repository for funds needed to raise a standing army (navy, air force, marine corps, etc.), because that's the government level funded by a progressive income tax. Those who consistently pay the highest marginal tax rates are either already rich/wealthy or they'll be that way soon enough. Since they have the most assets and property to protect from harm and invasion, it seems only fair and natural that they should be taxed disproportionately at the federal level, as they are today (at least nominally). Well, how about that - this aspect of our multi-level government taxing structure actually makes some sense.
As for which lives are put at risk for this protection service, well, that's another matter entirely, isn't it?