If your blood pressure is too low this morning, go read Roger Cohen’s “The Arab Withering.” It’s a couple of days old, and we weren’t going to mention it. After all, it’s lede reads thusly: “A little over five years ago I was with my colleague Robert F. Worth in Pierre Sioufi’s rambling apartment overlooking Tahrir Square in Cairo. Bearded members of the Muslim Brotherhood, their skin scarred by the torture of Mubarak’s security state, embraced secular Egyptian liberals and declared common cause. Young men and women…” But the thing has gotten a lot of reads, and it’s one of those pieces that drive us nuts: Not entirely wrong, despite its oversimplification, but the same pablum about intractable Mideast problems, the same stereotypes about what happened in 2011…