Know any sheepdogs?

http://www.humanevents.com/article.php?id=35832 
"One Vietnam veteran, an old retired colonel, once said this to me: "Most of the people in our society are sheep. They are kind, gentle, productive creatures who can only hurt one another by accident."

This is true. Remember, the murder rate is six per 100,000 per year, and the aggravated assault rate is four per 1,000 per year. What this means is that the vast majority of Americans are not inclined to hurt one another. Some estimates say that two million Americans are victims of violent crimes every year, a tragic, staggering number, perhaps an all-time record rate of violent crime. But there are almost 300 million Americans, which means that the odds of being a victim of violent crime is considerably less than one in a hundred on any given year. Furthermore, since many violent crimes are committed by repeat offenders, the actual number of violent citizens is considerably less than two million.

Thus there is a paradox, and we must grasp both ends of the situation: We may well be in the most violent times in history, but violence is still remarkably rare. This is because most citizens are kind, decent people who are not capable of hurting each other, except by accident or under extreme provocation.

They are sheep. I mean nothing negative by calling them sheep. To me, it is like the pretty, blue robin's egg. Inside it is soft and gooey but someday it will grow into something wonderful. But the egg cannot survive without its hard blue shell. Police officers, soldiers, and other warriors are like that shell, and someday the civilization they protect will grow into something wonderful. For now, though, they need warriors to protect them from the predators."
I'm grateful for the ones who run the wrong way, and remember well my time in that role. How long can one serve as sheepdog? How long should one hope to?