It's interesting that Dave W. cites the example of the obsolescence of the citizen soldier. The reason we don't have obligatory militia service is because our taxes pay for our military defense (supposedly, but in actuality the vast majority if for offense, to maintain corporate access to foreign resources cheap). In the same way our taxes pay for public works, so that we don't all have to own libraries, pay for private schools,  or toll roads. If we can spend more on our bloated military (53 cents of every tax dollar) than the next ten nations combined, many of them allies, then we can afford to provide access to Nature for all Americans, regardless of income.