In the United States today, there are no requirements for compulsory national or military service from our citizens. We are fortunate to have enough volunteers to serve in our armed forces so that there isn't a need to compel citizens to sign up for either national or military service. Some people would consider compulsory national service to be a form of involuntary servitude, but that certainly wasn't the viewpoint during the foundation of our country in which in colonial times, it was common for states to require compulsory militia service for all free males, so as to have sufficient forces and arms to repel invasions, insurrections, and to uphold the law as required. Militias were necessary in order to protect one's home and homeland, and the responsibility to do so, was a basic requirement of free citizens within our country, everywhere.
You can make a strong argument in which there is a lot to be said for all citizens being compelled for a mandatory period of time to serve their country via the military or the national service, so as to understand that freedom is never free, that sacrifice and teamwork are part of our national character and part of being an American citizen; that citizenship in America isn't necessarily a birthright, but something that entails duties and responsibilities to our fellow citizens and our country. Instead, we have a country in which to a large extent, our armed services are made up of peoples that are from below average national median income areas, rural areas with few opportunities, and also those trying to escape from the our generally poor economy especially for those that are not higher education qualified people.
The United States acts as the world's policeman, in which, perhaps, if all citizens were compelled to serve their country in some capacity, there might be more of a protest over our foreign adventures. It is always far easier to support armed intervention overseas, knowing that you or your loved ones, won't ever be in harm's way. If you do not have skin in the game, it's difficult to empathize with someone that does, despite the fact that that the cost of freedom is eternal vigilance.
I wish that we lived in a world in which we all got along, but the fact of the matter is that we don't. In order to try to fulfill our dreams of a world in which we recognize that we are all in this thing together, all of us need to spend time engaged with other people, other countries, and other circumstances, so that we can better appreciate and not take for granted the greatness of our own country but also to know and to recognize that it is not so much that the people around the world are so different than us, but instead to acknowledge their similarities to us.
It is high time to acknowledge not only our responsibilities to ourselves, but also to our fellow citizens, and ultimately to the world. The world is messed up, maybe because we are not involved in it as much as we should be.