For me, this is too narrow a definition. Also, can a non-believer blaspheme?
Thirdly, is an image of the Last Supper sacred? If yes, what makes it so?
> By going to such lengths to profane a faith at its
most basic level, isn't this an implicit acknowledgment
of the faith's power and importance?
How about: the undeserved "power and importance" of the faith, in the sense that it has and exerts power outside the circle of its believers?
> Doesn't this make the act of blasphemy somewhat superstitious
in itself?
Not at all. It is an acknowledgement that some faiths have leveraged their power far beyond what is desireable in a pluralistic, secular society.
> Second, consider, for example, the reports of U.S.
interrogators flushing of the Koran down the toilet to extract
information from Muslim prisoners.
First, I see no connection between the poster and interrogation techniques. You are making a leap of bionic woman proportions.
The question here is what are the permissible boundaries of interrogation. Is producing religious trauma in someone a bridge too far?
> Is there anything wrong this this practice in and of itself?
There is if you decide that inflicting emotional trauma is beyond the proper boundaries of interrogation.
> My sense is that there's something wrong with this (akin to
the Nazi humiliations of religious Jews: making them shave
their beards, etc.) although I can't exactly put my finger on
it.
But you did put your finger on it: such actions are intensely humiliating. The question is whether or not it is acceptable to humiliate a person when interrogating her.
Brian