As much as I would love to blame Obama for the lack of security, Ollie North read a 2011 security directive the other day that gave commanders the ability to arm contingents on their command if they felt the security situation called for it.
Since we have been warned that we are targets in the US, and since there have been prior attacks, it would seem to me that the security situation calls for it. Barring another directive or instructions, this would put the responsibility for making our people unarmed targets, on the COs. If they had the ability to provide security, and the warnings that it was needed, and failed to provide, the blood is on their hands.
There seems to still be some hesitation on the part of some of the COs which makes me wonder what they might have been told that we don't know. The MC said screw it and they are arming security, and the Navy is doing the same with the MPs stateside.