For a practitioner of love and compassion, an enemy is one of the most important teachers. Without an enemy you cannot practice tolerance, and without tolerance you cannot build a sound basis of compassion.
When we speak of a calm state of mind or peace of mind, we shouldn't confuse that with an insensitive state of apathy. Having a calm or peaceful state of mind doesn't mean being spaced out or completely empty. Peace of mind or a calm state of mind is rooted in affection and compassion and is sensitive and responsive to others.
There is a common perception that compassion is, if not actually an impediment, at least irrelevant to professional life. Personally, I would argue that not only is it relevant, but that when compassion is lacking, our activities are in danger of becoming destructive. This is because when we ignore the question of the impact our actions have on others' well-being, inevitably we end up hurting them.