Really?

That would negate all the training the military of every country gives in killing. It would make the work to overcome the natural aversion to killing others ("You shall not kill") irrelevant -- give someone a firearms and they'll kill with it, even if they've never held one before.

I strongly urge you to read titles like Keegan's "The Face of Battle", Grossman's "On Killing" and "On Combat", and S.L.A. Marshall's critique of US marksmanship training before saying more. Make a real study of violence and stop spewing out pre-digested pap.

Then go visit a veteran's hospital and talk with some of the people there. Tell them that the mortar round that took their legs off or the sniper shot that spattered their buddy's brains all over them weren't done by people who intended to kill.

Two things are necessary NOW, in the US and elsewhere:

1. Good, solid mental health programs without the stigma of "crazy" or "weak"
2. and sensible, logical, and consistent firearms laws.