I think it should be mandatory, not for any sort of patriotism or need to defend the country, but because Boot Camp alone can really help people, especially just out of high school. It teaches you how to work as a team, self respect, and if they serve 2 years like you mention, then they will potentially have the time to experience the rest of the world, instead of just the town they grew up in. Worldly experience goes a long way in fighting off stupidity.