While Haruka seems cocky and self-assured to the outside world, she is a very tortured individual. This is especially noticeable during the S season. From the beginning, she fought a powerful internal conflict regarding her duties as a senshi. At first, she fled from her identity as Sailor Uranus and the idea of sacrificing innocent lives. While she eventually embraced the Machiavellian philosophy that the Outer Senshi are known for, she continued to feel like a terrible person--although she acted for the benefit of the world. This proves that:
1) She's very hard on herself. She knows in her mind she must take the ruthless actions she does. She justifies them to the Inner Senshi, but inside she feels that her hands are tarnished by the sacrifices she is willing to make.
2) Haruka is not a dangerous, crazed zealot who thinks she knows what's best for the world. She, too, has doubts. Come on now, people, Haruka isn't almighty!

Secondly, her jealous possessive nature screams of insecurities. Michiru is irked when Haurka flirts with other girls, but Haruka grows extremely jealous over incidents as simple as autograph seeking males talking to Michiru in the manga.

Moreover, Haruka seems afraid of losing anyone who's close to her. She's extremely proective of both Usagi and Michiru and very suspicious of any presumed threats (Seiya, for instance). In our opinion, Haruka's vulnerable moments truly define her character, especially in regards to her strong, courageous ones. They humanize Haruka by showing that her macho front is just that: a front.