And yet, people frequently dismiss it as a "libertarian meme." One doesn't have to look far on the Internet to find someone that will deny that government enforcement of things like taxation or zoning regulations do not constitute violence.
What I meant by truism is that it may be a logically consistent position given the initial assumptions, but it brings no additional knowledge. If you accept the government=violence condition, then ANY law, rule or regulation is upheld by violence.
When you don't pay alimony: violence. When you jaywalk: violence. When you litter: violence. When you wear shorts instead of trunks at the swimming pool: violence...
OK, great, we've established that there is violence everywhere. But what has that brought us? Nothing.
I'm just using the definition that seems to be the first one listed in many English dictionaries.
"Violence is the intentional use of physical force or power, threatened or actual, against a person, or against a group or community, that either results in or has a high likelihood of resulting in injury, death, psychological harm, maldevelopment or deprivation." http://en.wikipedia.org/wiki/Violence?redirect=no
Your last two definitions don't fit unless you've a priori decided any government action is abuse - which is the wrong way to define things. Your first definition is so belaboured and tortuous that it sounds like libertarians have been at it.
And it's interesting to note that none of your definitions allow for natural phenomenon to be violent, yet we quite naturally talk about things like violent storms in English.
It sounds more like a rhetorical truism than a "true idea". Of course the police enforce the laws, that's what they're there for.