Most of your application credentials are determined by end of Junior year.
Your GPA on application will only include 6th semester [Junior year] and you will have SAT / ACT scores by then as well.
The intangibles are the leadership / athletic components and the reasons for your international interests. i.e.: Were you captain of varsity team junior year only to leave? Is the study abroad a natural extension of ongoing interests or just something you wanted to do? Can you continue participation in athletics / physical training while overseas?
Its not an automatic negative or positive IMHO but be prepared to explain why you chose this in light of your interest in a military leadership career.
[again IMHO 'Something I always wanted to do' might not be the response that gives you the edge.]
