Against which party? I don't trust Orwell's judgement -- fighting for POUM, and making the argument above, weren't the only errors he made -- and I don't think Gladwell should have trusted it either.
(But then, Gladwell wrote a book called _The World is Flat_ in 2000, and it was about free trade, not fundamentalism; he's not exactly someone who I look to as a paragon of good judgement either.)
POUM was anti-Fascist and anti-Stalinist. If you think it was an error to support such a party in Spain at that time, I'm afraid it says more about your judgement than Orwell's.
(But then, Gladwell wrote a book called _The World is Flat_ in 2000, and it was about free trade, not fundamentalism; he's not exactly someone who I look to as a paragon of good judgement either.)