Here is an excerpt from my review of Evan Thomas’ Ike’s Bluff for The New York Times:

The Hungarian uprising of 1956 stands out as one of Eisenhower’s best and worst moments for his policy of “take a hard line — and bluff.” Though he successfully avoided a major war with the Soviet Union over Hungary, choosing containment over confrontation, his administration’s rhetoric about “rolling back” Communism unfortunately encouraged Hungarians to expect American support that didn’t come. The Soviet crackdown in Hungary also exposed the limitations of the C.I.A. under Eisenhower. The agency was surprised by the Soviet reaction to the uprising, but as Thomas says, “C.I.A.-backed clandestine radio stations” had been encouraging Hungarians to fight.