Government as an idea is not evil, it is an actual necessity. However, due to the draw of power on the ambitiously corrupt individuals (individuals that make up the collective entity of "government"), governmental powers must be held in check by the governed.
Once the ability for self defense is removed, there is no actual check. This was the purpose for the 2nd amendment.
Totalitarian governments under "auspicious" leaders such as Hitler, Mao, Stalin, and others, first forced registration of arms to find out where they were, then confiscated them. After means of resistance are removed, it is quite easy to do whatever you want to a population regardless of how loudly they cry "foul".
I wasn't even referring to just war, I was referring to the amount of genocide at the hands of governments (through the military, which is pretty much always an extension of the government, or in many 3rd world cases, is the government).