Right, TNF. The military has the same rights that any other organization, sans something like alcohol or tobacco companies, to go advertise to people. The state can limit free speech if it has a specific reason to do so, yes, but I don't see a valid reason to ban military recruitment. They aren't forcing anyone to sign up. They are recruiting volunteers. Just as all advertisers do.
What interest does the state have in limiting their freedom of speech?
That, then, is the question, whether the military is more like a tobacco company or one that sells car insurance, and I think a good argument can be made that the military is like the tobacco company.