It isn't that I want our troops to be in greater danger... obviously. That said these pictures are of actions committed in the past, thus I believe owning up to this past will in fact create less danger for our troops in the present. Transparency about our wrong actions is a strong Mia Colpa that could indicate to people in Afghanistan and Iraq that we take our mistakes seriously and we intend to do the right thing...
Lets look at it from the angle of a potential insurgent. You've been taken over, you've not had consistent electricity for a long time, the toppling of the dictator didn't make things utopians. These westerner soldiers have been controlling your country for too long now. You've seen some torture pictures from Abu Girab (sp), you've heard about people flushing the word of God down toilets like its poop.
Then those who occupy your country elect a new guy, one who claims to not want to continue occupying your country. You pause and reflect waiting to see if this is for real.
He begins to open up about the use of torture. That seems good to you, maybe his other claim, that he really IS trying to get our of your country, is true. Then all of a sudden he decides not to show these pictures of torture... he reverses himself! Then you start to think, perhaps he will reverse himself on this whole occupation thing too...
I don't know, I guess I should give the president the benefit of the doubt, but to me it seems like a flip-flop and an indication to the world that we're maybe not as confident in rule of law and the idea that the truth will set us free as we should be and often claim to be.