We learn a bit more about Ensign Kim in “Emanations”, as he accidentally gets stuck in a first contact situation. Then, the show gives us its best episode yet, “Prime Factors”, which lays bear exactly how precarious their position in the Delta Quadrant really is.
Trekabout Episode 242: Emanations/Prime Factors

Cliffy73
-My comments on the previous topic notwithstanding, I disagree with you and Tim Russ about Tuvok in this episode. I found his motivations eminently clear. As a tactical and security officer, he knows and accepts that it his his duty to give his life, if it becomes necessary, in service of his captain and his crew. If he could get them home by giving his life, he wouldn’t hesitate. So, as a Vulcan, why is his honor or his career more important? It’s not. I like this reasoning because it makes Tuvok, and Vulcans, fundamentally alien without meaning we can’t be friends or allies.