You go climb every mountain.
UPDATE: The killer was a 34-year-old Spec 4. That’s a lot of years for such a low rank. He either joined late, never deserved promotion or got busted along the way.
And, no, I don’t think allowing non-police soldiers to carry loaded weapons on post is a good idea. Investing in a few metal-detector wands for every person and car that passes through the gates would be a better one.
THE TEXAS SCRIBBLER 
As you know, in our neck of the woods everyone carries his weapon at all times. And I cannot say that we have an abundance of shootings on the bases. But of course, it will be impossible to extrapolate to US, it’s a completely different environment.
Back in my day (67-71), only military police carried loaded weapons on post. Since we’re not a homogeneous society like Israel mostly is, no I don’t think it would work. There might not be any massacres, but there would be shootings and fairly regularly. The Army can stop these guys from bringing pistols from home but they apparently don’t want the expense or inconvenience involved. When these massacres start cutting into recruiting, then we might see some change.