Pipes has his biases, both as a Pole and as a Cold Warrior hawk among hawks, and an ideologue as a historian (don't think the Jewish part is relevant here), but he's also a genuine expert i.e. knows the subject inside and out. He's not some think tank pundit with lots of opinions and no real knowledge, nor is he some guy writing for an expat publication, or a Russian who feels he knows the subject just because of his nationality, or some blog comment writer. FWIW I find his later historical work rather poor, but the earlier stuff great.  He has also been complaining in the Polish press about needless provocations of Russia.