"They asked various political leaders and generals to evaluate the probability that the USA would withdraw its ambassador from the Soviet Union. They then asked

"They asked various political leaders and generals to evaluate the probability that the USA would withdraw its ambassador from the Soviet Union. They then asked the same people to evaluate the probability that both (a) The USSR would invade Poland AND (b) as a consequence, the USA would withdraw its ambassador from the USSR." This seems to be worded funny, such that it is easy to misconstrue that as the conditional "If the USSR invades Poland, THEN the USA would withdraw its ambassador". That is, the consequence is not viewed as separate from the condition if the subject considers the consequence as the only possibility of the condition, then the condition portion occurring alone and the condition and the consequence occurring have exactly the same likelyhood in people's minds. After all, the consequence has no reason to occur if the condition isn't met. The USSR invades Poland and it snows in Florida are two events that, if taken together, have a smaller chance of being true than either of them occurring independently.