Yesterday, the military backed up its claim that Iran is fueling the violence in Iraq by showing reporters a PowerPoint presentation that contained evidence on bullet hole sizes, bomb construction, etc. Together, the evidence was supposed to make the point that Iran is arming and training extremist militias in Iraq.
It's an interesting story because (1) the Bush Administration is taking a much more public tack in its allegations against Iran than it did with Iraq, (2) it makes me even more worried that we are headed for a violent confrontation with Iran, because otherwise why would the Bush Administration be putting justifications in the public sphere, and (3) the evidence is already running into skepticism.
See the PowerPoint here. Read Josh Marshall's very good "So What?" response here. Read Juan Cole's very detailed "Bullshit!" response here. See General Peter Pace already back off the assertions against Iran here.