Its the military. There isn't much of an interview, other than if you are able to join. Verify minimum physical fitness, education, and drug test. Seek available jobs to suit your needs.

Upfront and personal. They ask you questions and you answer them, they will ask about drugs a thousand times and possibly in a thousand different ways. Don't try to flatter them or try to be a cool guy, it's only going to make you an office joke the second you walk out that door.