Supporters of the Saudi arms sale made many bad arguments yesterday before the vote, but this may have been the most laughable mistake:

Two longtime senators leaned on questionable geographic analysis Wednesday as part of their successful defense of a $1.15 billion proposed arms sale to Saudi Arabia.

The Strait of Hormuz would be threatened if Houthi rebels had taken over all of Yemen before Saudi Arabia launched a military intervention last year, they agreed before leading colleagues to shoot down a bid to block the arms sale.

But the shipping bottleneck actually separates Iran and an Omani peninsula hundreds of miles north of Yemen, where Shiite rebels and backers of a deposed and formerly U.S.-supported strongman are resisting a Saudi-led campaign that has killed many civilians.

McCain and Corker’s error would almost be funny if it didn’t reflect their poor understanding of the region and the conflict they want the U.S. to continue fueling. Corker is the chairman of the Foreign Relations Committee, so one would think he would have better familiarity with the geography of a part of the world where he wants the U.S. to be so involved. McCain is famously treated as a foreign policy “expert” despite a long record of horrible judgments, so his screw-up is even more ridiculous. Their error is significant not only for betraying their ignorance about basic geography, but also for showing how desperate they are to make Iran a major player in the conflict when its role is actually limited and not very significant. When Corker answers McCain’s question, he says that “it puts more of that in Iranian hands,” and that is based on the lie that Iran has any control in any part of Yemen. This matters because McCain and other backers of the Saudi-led war are determined to portray the war as “self-defense” against expanding Iranian influence, but neither of those things is true. It’s hard to see why anyone should take McCain and Corker’s views on the conflict seriously when they can’t even be trusted to read a map correctly.