I mean, almost nothing

Depends on the problem, but Calvin is largely correct.

And the people.

Violence begot nothing but more Violence yet peace can forge peace but without strength shown trough Violence there can be no peace

So violence begot nothing but more violence and also peace?

Yes

I think violence is a poison whose effects depend entirely on dosage, except unlike drugs it's the smaller doses that cause the most harm.

Doesn't matter which one, but if either side of a 2-sided battle was fully eradicated, that particular conflict would be over for good. It's the half-measures that keep people fighting and dying for generations. Not that there's any such thing as lasting peace anyway, or even the possibility of it.

Solution to everything then it to eradicate everything

No need to rush into it. Entropy does that for us constantly whether we like it or not.