The Military Commissions Act of 2006: A Short Primer(I cut to the applicable section, although this entire piece is a worthwhile read)
.. the legislation narrows the scope of the War Crimes Act of 1996, decriminalizing certain past acts. Previously, the War Crimes Act criminalized all violations of Common Article 3 of the Geneva Conventions, as well as grave breaches of the Geneva Conventions. Anyone responsible for any Common Article 3 violation, including the cruel, humiliating or degrading treatment of detainees, could be prosecuted under the law.
The MCA revises this portion of the War Crimes Act, replacing the blanket criminalization of Common Article 3 violations with a list of "grave breaches" of Common Article 3, which are specified and defined in the legislation. And the law is amended retroactively to November 26, 1997, meaning that perpetrators of several categories of what were war crimes at the time they were committed, can no longer be punished under U.S. law.
Now, under the MCA, torture and cruel and inhuman treatment qualify as "grave breaches," but degrading or humiliating treatment does not. The MCA also eliminates as a war crime the passing of sentences by a court that does not meet international fair trial standards.
A twist in the new legislation is that it includes two separate definitions of cruel and inhuman treatment, one that applies to abuses that occurred prior to the MCA's passage, and another that applies to future conduct. If committed after the passage of the MCA, cruel and inhuman treatment only requires a finding of serious and non-fleeting mental pain or suffering. But for abuses committed prior to the law's passage, the perpetrator can only be penalized if the pain or suffering is "prolonged." (More)
http://www.deathpenaltyinfo.org/node/1830 The Military Commissions Act of 2006 basically re-defines "war crime" as set forth in the War Crimes Act of 1996 and Geneva. While it is not a pardon,
per se, it provides a high level of immunity from prosecution for past and future actions.
The Constitutionality of the Military Commissions Act might have (nay,
should have) been challenged had Nancy Pelosi pursued the impeachment of Bush and/or Cheney. Let us hope that a new Democratic Congress and a Democratic President address this egregious piece of legislation early in the next year.
The MCA pardons no one. However, like the FISA Modernization Act, the MCA makes certain crimes (known to have occurred) legal, retroactively.
Take heart that there are plenty of Bu$hco crimes that are still unknown to us for which there is no immunity in law. That is not to say that Bu$h will not exercise his Constitutional prerogative and pardon the whole sorry bunch, but most Constitutional scholars agree that the President cannot pardon himself. Much has been written on the subject, with particular angst in the case of the right-wing when contemplating a Clinton self-pardon in the 1990s.
Also, I would highly recommend DUer David Swanson's piece "President's Job Is To Pardon" of this past August:
http://www.davidswanson.org/?q=node/1415