This is a tricky subject because it's something that can easily be compared to pass or existing programs that may not be seen as being very 'American'.
To help the discussion I define National/Civic Services as such:
National Service: Army, Navy, Air Force, Marines, Coast Guard, National Guard. Basically military service.
Civic Service: Police, Fire, EMT, Nursing, etc. Localized non-military services that help the community.
I suggest that a combination of these two into a single conscripted service be implemented in the U.S.A. This would be a service that all citizens would be required to participate in, at the age of 18. Certain intellectual and/or emotional tests would have to be used to determine the eligibility of some people to take certain jobs, but most would be able to select how they serve.
Since there would be non-military options available conscientious objectors would have nothing to object to. Your beliefs don't allow you to become a killer, fine. Be a nurse, an EMT, fire fighter or other service provider that saves lives.
I think this service should be at least 2 years long but no longer than 5. Individuals could stick with their service of choice if they so desired. Those who were done could go on to college or the job market.
Why do this? It's really quite simple actually. The United States is a rich country. Because of this wealth and the large divide between the wealthy and the poor, the poor have few opportunities to break the cycle they are in. Additionally the rich are wealthy enough to avoid civic duties. That leaves the middle-class to pick up the slack.
Of course there is the obvious benefits to the country as a whole. Services that are weak could be bolstered. Public works projects that improve the lives of all could be better undertaken. Look at our transportation infrastructure. Roads falling apart, bridges collapsing, counties and states fighting about who's responsibility it is to fix a problem. Nationalize the public transportation system and put civic service workers on it and we'd have the best roads in the world in a few short years. This is just one example, there are many more that don't even require nationalization of anything. I know that scares some people. Some see that and think communism. Looking at the state of our roads, do you really think it's working as is? How many hours of your life have been wasted surrounded by orange barrels because of current inefficiencies.
Look at the shortages of nurses. Sure in a short period of time you couldn't train someone to be a top nurse (most are just as knowledgeable as the doctors!) but you get some with at least EMT level training and they can do a LOT to help. Additionally there is a huge need for nurses in nursing homes, hospices, and to help care for the mentally handicapped. Don't you think that if Paris Hilton in her spoiled teens had suddenly been forced to train and assist a handicapped poor minority that it might really have an impact on her life moving forward? Things like that change people. How about the womanizing jock in high school that suddenly had to face the realities of rape and other sexual assault in a safe house? Suddenly his perspective is changed for the rest of his life.
The point is that it's not a bad thing to be forced to do something you wouldn't have volunteered for on your own, especially in those early adult years. Sure they might not be very happy about it at the time, but afterwards (maybe right away, maybe years later) they would be able to appreciate the time they spent then and how it shaped their life.
There is also a sense of pride that is gained by doing those things. That's something a LOT of people NEED. The kid who grew up with low self esteem is going to feel a lot more confident after he helped save a life or two. How about the girl who grew up thinking that women were inferior (unfortunately that is still taught)? She stands shoulder to shoulder with her fellow male police officers, doing just as much good.
We'd have a generation of people with civic and national pride that is based on something meaningful, not propaganda or fear.
I don't want to suggest that those individuals who are in these various civic and military services are some how inferior or anything, in fact they are really great people for doing what they do, without being forced into it. It doesn't take much of an argument to see that there are many many people who'd never do this voluntarily and the country is poorer for it.
On a side note, but related, this program could also be used as part of an immigration program. Want to become a citizen? Ok, but before you can, you need to serve the country.
I've had it suggested to me that if you are going to force people to do this you should pay them. Sure, but at a reduced rate. They shouldn't be paid as much as those who choose to do that work beyond their required time. To do that would provide a disincentive and you'd loose valuable knowledge and experience. College grants could be provided as well as college credit within their field. A service nurse might be able to test out of or by-pass some early nursing classes.
There would have to be some rules that would put some people where they don't want to be. Let's face it, a small town of 200 people doesn't need 20 nurses. In those cases the local quota might be full. They could look to move to another part of the state or country. In those cases the move should be covered by the program. In other cases a person may not be mentally capable of performing certain jobs. Those individuals might have a smaller selection of jobs.
This is were there is some danger of abuse however. Some very clear factors would have to be set regarding mental capacity or individuals could be pushed into the jobs that others don't want because the quota needed to be filled or someone paid off and official to get their kid into a job they shouldn't have been in.
As time and social-political tides change it may be difficult to fill some of the military quotas. In war time are all the civic quotas going to fill up leaving a disproportionate number of people with little to no choice but to join a military service? That's a real danger. I would counter that with the Iraq war. As unpopular as it has been, there have still been a good number of volunteers. Some criteria have had to be adjusted to allow some new solders to get in that wouldn't have a few years ago, but that's going to happen. In peace-time why not have the best of the best. In war time when the best aren't knocking on your door, then the second-best are going to be just fine.
So is my plan perfect or fully fleshed out? No. Nor do I expect anyone to really take it seriously. It's too big of a program and there are way to many obstacles that would block it. It's an interesting thought experiment and I invite others to debate it. Shoot holes in it, argue with me, but only if you are going to do so intelligently.