There's Strong. Then There's Army Strong.

The audience of this advertisement is definitely seniors in high school to college students.
The tone of the text is one of aspiration, joining the army makes you a better person and opens up a lot more doors later on in life.
It is definitely temping to persuade the audience into believing that the U.S. Army is serving a greater good and if you join you will have a greater sense of self worth in your life.
It definitely tries to appeal to the reader's emotions because if you join the army you will become a better person. Also, it is trying to establish it's credibility because everyone knows how incredible the U.S. Army is and how much respect they deserve.
The purpose of this text is to recruit young men into the U.S. Army as a career.
Yes, I believe this text is definitely rhetorically effective because the advertisement makes the reader believe in the message it is trying to convey.