Rahere... I do not question your background and your basic knowledge of how intelligence is gathered and mistakes can be made in doing so.... and I even acknowledge your noting of the problem of "... the accountability of the CIA to its commanders.". These things are not in question, and have been noted in (some of) our media.
   I also note your account of various UK personnel being interviewed and taken to task for flaws.

As to: "IS the Head of the CIA changing their procedures to stop this happening ever again?" He indicated that he is... but without details, as one would expect.

My concern in your post is the change in tone/flavor/direction once you have explicated the obvious. You say: " Not everything is well in the UK, but when things are bad, we do what's necessary to sort it." This implicitly assumes that the US is not, and sidesteps the issue that I have noted before, that the steps "necessary to sort it" are intrinsically different than in the UK. It may be that yours are more efficient, or transparent, or even less political- I can't judge that. It is simply that ours seem to have a different and more complex set of constraints- including the makeup of various Congressional committees (which are about to get even more so as the #@*&%$ Republicans get control in January!)
There simply is not a comparable process here to 'to sort it out'. You may consider this to be a serious flaw, but it is what it is... and changing **that process**, like our frustrating process of choosing our political leaders, is subject to the same political awkwardness. It is when you make the shift from noting the problem to suggesting that 'we', as a nation, somehow fail to take relevant action, that I shake my head in frustration.
There ARE efforts to 'sort out' some of this nonsense, and no one is more concerned than I at the roadblocks...(well, no, I'm sure there are many just as concerned as I).

Some, like GfS just above, find refuge in the 'everyone is equally guilty' simplification, and 'Guest' just below that wants to suggest that *Obama* does everything. He does NOT.... it is NOT the case that all decisions flow over his desk for specific approval!

This summation ", both sides of the political spectrum, reducing your entire political system to "a penny-ante bunch of shysters" for taking authority but not using it. It's not pleasant, but it is real." just glosses over the true situation, but I can no more force YOU to see all the grays ...instead of blacks & whites... than I can remake out political system.
I have joked to friends for many years that "when I am made Emperor of the Universe" it will all be better....sadly, my nomination has been withheld.