One of our presidents was in ROTC and a very vocal proponent of the program. It didn't matter one way or the other, even though there were some people who were not big fans of the program...she left it at the door when she came in to sorority so no one really cared.
It's not like you have to get a crew cut when you participate in ROTC

....the only thing I can think of that would be a problem is if activities conflict and you should be able to work that out. If anyone would think there's something wrong with it, you don't need to be there.