It is impossible to say how many members of the armed services would have survived attacks on them during the past few years had they been, well, armed.

But Pentagon policy is that service men and women at many facilities, including recruiting stations, cannot carry guns, Americans have been told. A reminder of that came after four Marines and a sailor died in an attack on a Chattanooga, Tennessee, recruiting center.

Across the country, some civilians reacted to the ban by getting their own guns and standing guard duty at armed services recruiting centers.

Now, it develops there never was such an ironclad policy.

Defense Secretary Ashton Carter said this week that under some circumstances, personnel at facilities such as recruiting centers and ROTC offices can carry weapons.

Good.

Terrorists have targeted U.S. military personnel. Not allowing them to defend themselves was a mistake.