Seriously guys? Guns are not some magical object capable of stopping an assailant in their tracks. I mean, go play some paintball or airsoft and try and take somebody down while under fire, and that's hard enough without a classroom full of kids in the way and an attacker with superior firepower. If some dude with an AR is in your classroom lighting the kids up, you're dead before your gun is drawn.
Not to mention that if you have armed teachers, it's not going to be long before a teacher gets sick of carrying that metal lump around on their belt, takes it off and sticks it in their desk or wherever, forgets it's there, and next thing you know you have a kid finding it and ending up dead or shooting another kid.
Where I grew up, we had armed cops in schools and metal detectors at the doors. That's a more effective deterrent than giving guns to teachers. So is installing reinforced doors with automatic locks in classrooms.
No need? The police have them. What happens if the police oppress and threaten me with their assault rifles, how am I supposed to defend myself? And the military has a whole helluva lot more where that came from. What if the National Guard comes rolling down the road, how to I protect myself against that?
You may not realize why the Second Amendment was put into place. Our Founding Fathers believed that all humans enjoyed three basic rights, God-given as they called it, logical truths as I call it. The first one is the right to life. They just came out of an era where the British rules civilians with their guns, and there were numerous unjust deaths by British guns throughout the period. They knew that the only mechanism the institution of government operates on is that of force, and they realized that for people to be able to protect their lives from overzealous force there must be a clear protection of the means with which to protect those lives. The Second Amendment protects the peoples' right to bear arms - arms being weapons by definition - and does not specify what types of weapons. We can argue about the original capitalization of the word Arms, a proper noun, which seems to cement the definition as any weapon. An aircraft carrier is just as much a weapon as a bayonet and the Second Amendment makes no differentiation between them.
It's as simple as that and I can't wrap my head around how people can argue with it. The damn thing says arms which means weapons. It does not say what kind, it just says weapons. It can't get any simpler.
It says "a well-regulated militia" before it says anything about arms. Federalist Papers 28 and 29 deal with the meaning of this statement and the structure of the militia, which is to be composed of leaders appointed by state governments and lower-ranking members approved by the government. They are to be regularly inspected and drilled. Federalist Paper 28 explains the opinion of the framers that individual citizens attempting to defend themselves from a tyrannical government will be an ineffective force that will be quickly crushed and that it is state governments and their regulated militias that can protect the people from the federal government if necessary.
The vast majority of constitutional scholars agree with this interpretation, and so did the Supreme Court until the mid-2000s, when a number of extremely political members were appointed and the court reversed its long-held stance on the issue.
If the US Army comes rolling down the road, it's the job of the National Guards of all the states to stop them. If your state National Guard comes rolling down the road, then the federal military comes to stop them. Of course, this really isn't even an issue in the eyes of the framers of the constitution because both forces, especially the state guards, are composed of normal people from the community who will not act against their friends and neighbors.
By the way, I'm not anti-gun, and I'm not anti-"assault weapon." However, I'm not going to let my own feelings on the matter delude me about what the constitution means. If you ask me, what we need for the gun problem in this country is mandatory registration, strict background checks, mandatory secure storage of guns, and severe penalties for not reporting a gun lost or stolen if it's no longer in your possession, for possessing a gun you shouldn't have, and for using a gun in a crime. When NYC increased its penalties for carrying an illegal gun from a misdemeanor to a serious felony, their gun crime rate fell dramatically. Why hasn't this happened everywhere else?