Nope. It's totally optional, but of course it depends on the unit you get assigned to and your MOS.
PM me Jimbo, I've seen the Army from many different sides, I can give you the good and bad, and believe me I've experienced both. However, I'd still do it again, EXCEPT I would have done it before college instead of enlisting after college. If I would have done that, I would have retired last year. As it stands, I got out after 14 years. Family obligations, you know. I was missing too much and I really wanted to be there for my family, not off on a mission or in the field training, sneaking back to the rear to find a pay phone to call home every night.