Time and again-from the collapse of the Soviet Union to the...

Time and again-from the collapse of the Soviet Union to the events of 9/11 to the onset of the Arab Spring-events have caught the experts, whether in government or on the outside, completely by surprise. Business owners with comparable performance records go bust. Brokers lose their clients. Physicians get sued for malpractice. Yet think-tankers and policy wonks continue to opine, never pausing to reflect on-or apologize for-their spotty records.