Yesterday, there was an "lone wolf" shooting attack at a recruiting station and then a Navy Reserve station in Chattanooga, TN. 4 Marines were killed and a Marine and Sailor were wounded. The shooter was killed by local police responding to the scene. He was a Kuwaiti immigrant who had attended high school and college here in the U.S. He used a firearm (purportedly some form of semi-automatic rifle) in his attack.
It appears that the feds need some sort of security arrangements at these military facilities that include armed people. It would be relatively inexpensive for some military units to assign this duty on a rotating basis to personnel assigned to a particular facility just as they have done in the past. It was called guard duty.
I remember that I stood guard duty, armed with an M16 and ammunition, at a small arms repair facility at Fort Jackson before I had completed basic training. Certainly combat veterans can do the same at recruiting stations (the Chattanooga facility was NOT the first recruiting station that had been attacked). However, this will not be a fail-safe solution. Don't expect the military (for many reasons) to reverse the "gun free zone" approach.
The military leadership really doesn't trust the enlisted folks to be armed unless they have officers present to "control" them. This mindset is intrinsic in military thought to the point that for centuries NCOs and junior enlisted have been awarded high level medals for taking charge and leading men in combat without an officer present. This attitude precludes arming of service people all over a base. There is also the unstated thought that a certain level of loss is acceptable. Further, the President does not want to undermine his agenda of civilian disarmament by obviously arming the military in their day-to-day domestic operations.
We know that these attacks will continue and can only hope that something is done, even if on the "down low", so that the Jihadists are stopped in their attacks.