When is violence actually the answer?

Always. Whether we like it or not, violence is the supreme authority, from which all other forms of authority are derived. The secret is creating people who understand this while being enlightened enough to use it as a last resort. Instead what we have today is a people who think violence is never the answer, and as a result their world is being overrun by those willing to use that power.

Self defense mostly, or if you're trying to protect someone you really care about, which falls under the self-defense category. But don't pick fights. If they don' start fights with you or anyone else, there's no reason for you to go swinging at them.

self defense or defending something that is being accosted unjustly

When somebody tries to to hurt you physically

"NOW!!!"

Nothing comes from violence, nothing ever could. Sting

[youtube=http://www.youtube.com/watch?v=lB6a-iD6ZOY]

If a person is violently attacking you. Which is self-defense since you're trying to stop them from hurting you, physically.

When back up in a corner and there is nothing else to do, then that's when it's necessary.

when someone puts their dick in your food.

In any Quentin Tarantino movie.

When they strike first!

When someone tries to harm me or mine.

When it's in defense of oneself or another.