There is a number that is used to determine how much security is needed per number of people. One only has to look at a population of a city and divide it by the number of "police" officers to arrive at a figure we can work with here. Let's say one police officer per 750 people.
In a school setting, we can have thousands of "un-disciplined" children and young adults running around daily. Yet, they are not protected at all. Is it not the duty of our "police" organizations to protect? Why not "kill two birds with one stone" here? With one armed officer, say per 750 people, our society receives the protection our tax dollars pay for and the kids, because of the police presence, behave with a little more discipline. It is their duty to "protect and serve."
Maybe discipline is not what is wanted. After all, we have quite a few very large corporations building prisons for profit all over this free country. With less than 5% of the worlds population, the US has over 26% of the worlds prisoners. Are we really that bad?
We need more discipline in our classrooms, period. It is where our kids spend one third of their lives during their formative years!!