This points out the inherent contradiction of public schooling, more accurately termed state-run propaganda camps.
In a free society, in which all schools would be privately owned, parents and school administrators would determine what the correct mode and level of defense should be. Most likely, they would opt for certifying teachers and administrators in armed defensive techniques, as the Israelis have done. Such an approach is low-cost and very effective.
But in a free society, there would be no need for public debate and a one-size-fits-all approach to the issue.