The principle is pretty basic: if we don't know what happened, and who did it (whether we prosecute or not), and we don't exercise a formal judgment on how bad it was, then all we do is enable those who would do it again, and destroy our image throughout the world.
Americans want this to happen.
But there are some significant problems here.
1) Too many people in both parties knew exactly what was going on and stood by. Raul Hillberg, one of the most famous Holocaust historians, created the dichotomy of perpetrators, bystanders, and rescuers, to which another historian (I honestly can't remember who ) added witnesses to separate those who watched and did nothing from those who risked watching to testify later about what happened.
We had far too many bystanders (enablers) among our Congressmen, in our military, in our law enforcement organizations, and even in the media, who knew what was going on and did nothing. Those people cannot afford any sort of investigation.
2) An independent panel is virtually an impossibility for pretty much the same reason. A truth commission ala the South African model is not a good fit culturally or historically. The events which led to the commission in South Africa with the end of the apartheid government and the ANC take-over were seismic, rather than what happened here. Besides, even the 9/11 Commission was riddled with political infighting.
3) The best answer, at least in the abstract, is to declassify it all and turn it over to journalists and academics. Unfortunately, that ain't gonna happen, in part because no administration is going to set that kind of precedent for outing it.
So what do we do? We cannot drop the issue, or pretend it didn't happen, because it goes directly to who we are as a people.
Sometimes there are no good answers, only answers that are not as bad as the worst might be.
Here's mine: don't allow the government to have control of this issue.
Yeah, yeah, I know--the crazy libertarian.
But this is the same way that I suggested that 9/11 truthers in the libertarian movement:
1) Pay for it yourself, in the form of a private foundation (called, oh, say, Libertarians for Justice). That way you are not coercing anyone else into paying for it, and you have complete control.
2) Use the funds you've gathered to (a) support a massive, private independent investigation. Overcome the lack of subpoena power and classified access by offering a $1 million dollar bounty and guaranteed legal representation to any whistle-blowers or leakers who bring forward the information.
3) Once you have established credible information regarding the culpability of individuals in the conspiracy, file a series of high-profile "wrongful death" civil suits against these individuals, as well as publicizing and turning over all materials to local and state prosecutorial officials.
George Soros, T. Boone Pickens--where are you when it matters?