What if joining the Peace/Ameri Corps was mandatory in public schools in the United States following graduation of high school?

Joining the Peace/Ameri Corps is not only a form of charity, but an educating experience in itself; one that is beyond something that can be taught in books or anything teachable in a classroom. The lessons and knowledge gained through the volunteer programs help provide and educate a new prospective to other cultures and ideologies in the world. What if it were mandatory to join one of these volunteer programs (Peace Corps, AmeriCorps) for a certain amount of time upon graduating high school? What would be the benefits/drawbacks? Could this ultimately effect the skewed public educational system in the United States and the non-progressive standard path taken by high school graduates?