The Buddha says that the way of undertaking things that is pleasant now and ripens in the future as pleasure dispels darkness with its radiance. Cultivating prajna (or higher wisdom) guides us to make choices that bring about more happiness in our lives.
Practicing meditation, we inevitably encounter the wandering mind. Rather than considering this experience to be a "problem", if we explore this phenomenon with mindfulness, we can learn a lot about our minds.
The mindstates behind violence--anger and fear--are universal and natural. If they possess us and drive our actions, we suffer. If we learn to meet them with a mindful awareness--if we step out of judgment and angry reactivity--we serve our own freedom and the possibility of peace on earth as well.