I'm going to jump in here and make a few descriptions I think are missing. In terms of Obama himself being responsible isn't the correct verbiage. As politics as played us a nice hand everyone will quickly blame a president. We saw it with Bush since he apparently masterminded everything all by himself and Dick. Now the shoe is on the other foot and we want to downplay it. We gotta figure it out people. Technically, Southern Dad mentioned in his OP that this was a failure of the administration. You guys quickly jumped on him making jokes and acting as if Obama himself went into Yemen and f**k it all up. That's not even remotely close. In any company, organization, classroom etc, when people mess up on lower levels or other positions the individuals responsible are always top brass. Either they are blamed for a lack of response, a failed response or no response at all. It happens and quite frankly it sucks but its the truth.
In this case, Obama himself didn't mess anything up, but he is POTUS and commander in chief of the armed forces. Embassies, foreign policy decisions and military operations are his priority. Its not like him or higher ranked officials didn't know Yemen was deteriating and the notice for them to leave probably was made by state department officials with white house approval or acknowledgement. In terms of military items, it seems we probably got rid of the important stuff, but do M16's shoot people or shoot bean bags? Does ISIS currently use tanks for supply's and travel? Nope, they use vehicles purchased, shipped and protected by the US of A. If you've ever seen some of their cars they are simple suv's, trucks etc.
I know some of you like to make jokes at everything without thinking about the situation, but if we did in fact turn in weapons of any kind, whether its 50, 100 or 10,000 items then we probably just gave ISIS, AQ or others equipment for free paid by the US taxpayer. I know we are already upset as it is in regards to this. Then, in the grand scheme of things, this does reflect poorly on those who are making the decisions. Now I could make a statement that our individuals in the state department and elsewhere felt it would of been a greater security threat had they not handed over their weapons and other items, so I can always try to look on the other side of the coin. Depends on a lot of different variables honestly.