It is surprising to me -- perhaps it should not be -- that this vicious myth survives; as recently as 2005, some 20 members of the Russian Duma presented it as fact.
Interestingly, similar sweeping libels are still applied against other minorities and are still promoted as absolute truth by people who one would expect to know better.
There's a very simple yardstick for determining the truth of such talk: "Extraordinary claims require extraordinary proof." Not to mention an extraordinary degree of skepticism in evaluating. Remember, the simplest (and most directly personally beneficial) motive is usually the actual motive for people's actions, and vast conspiracies are only the stuff of spy novels. (Sorry, Mrs. Clinton!)
Is the NRA fomenting insurrection? Are homosexuals out to destroy your marriage? Is every swarthy cabdriver a mad bomber and lying to you as a matter of religion? Does Rush Limbaugh run the Republican Party? Probably not. On the other hand, George Soros and the Koch Brothers are indisputably political activists with their own agendas and if money talks, they're plenty loud. See how this works?
(Edited: I had typed "poof" instead of "proof," with the expectable result in Comments. Extraordinary, indeed!)
8 months ago