Summary
John McCain is attacking Barack Obama's opposition to the Kyl-Lieberman amendment, which (among other things) called for labeling Iran's Islamic Revolutionary Guard Corps as a terrorist organization. McCain claims that Obama's opposition means that he also opposed calling the IRGC terrorists. We find otherwise.

• Obama cosponsored an earlier bill that also called for designating the IRGC as a terrorist organization.
• The Kyl-Lieberman amendment did more than just label the IRGC terrorists. Obama stated at the time that he opposed the bill on the grounds that it constituted "saber-rattling."
• McCain claims that Obama must oppose calling the IRGC a terrorist group because Obama's Web site doesn't say anything about the IRGC. McCain's argument is a glaring example of the logical fallacy of argumentum ad ignorantiam.

Analysis
For the past two weeks, presumptive Republican presidential nominee John McCain and Democratic front-runner (and now presumptive nominee) Barack Obama have engaged in a war of words over their respective positions on Iran. In a June 2 speech to the American Israel Public Affairs Committee, McCain upped the ante, criticizing Obama's failure to support an amendment that called for designating Iran's Islamic Revolutionary Guard Corps (IRGC) as a terrorist organization, a charge that McCain repeats on his Web site. It's true that Obama opposed the amendment in question. But McCain is wrong to suggest that Obama's opposition had anything to do with the IRGC's designation. And McCain fails to mention that Obama cosponsored an earlier bill that would have named the IRGC a terrorist organization.

Wait, What Are We Fighting About Again?
Let's start with that whole Revolutionary Guard business. Here's McCain at AIPAC:

McCain (June 2): We must apply the full force of law to prevent business dealings with Iran's Revolutionary Guard Corps. I was pleased to join Senators Lieberman and Kyl in backing an amendment calling for the designation of the Revolutionary Guard as a terrorist organization responsible for killing American troops in Iraq. Over three quarters of the Senate supported this obvious step, but not Senator Obama. He opposed this resolution because its support for countering Iranian influence in Iraq was, he said, a "wrong message not only to the world, but also to the region."

On his Web site, McCain makes the point even more bluntly:

McCain Web site: The Kyl-Lieberman Amendment Designated Iran's Revolutionary Guard Corps A Terrorist Organization - But Senator Obama Opposed It.

McCain implies that Obama doesn't think Iran's Islamic Revolutionary Guard Corps is a terrorist organization. That's wrong. Before the Kyl-Lieberman amendment was introduced, Obama cosponsored a bill that called for the IRGC to be designated as "a Foreign Terrorist Operation." Obama was one of 72 cosponsors of the Iran Counter-Proliferation Act, which states (in part):

Iran Counter-Proliferation Act: The Secretary of State should designate the Iranian Revolutionary Guards as a Foreign Terrorist Organization ... and the Secretary of the Treasury should place the Iranian Revolutionary Guards on the list of Specially Designated Global Terrorists under Executive Order 13224.

The McCain campaign notes that the Iran Counter-Proliferation Act has yet to come to the floor for a vote. But that doesn't change the fact that Obama's sponsorship put him on record in favor of labeling the IRGC a terrorist organization, contrary to McCain's insinuation.