I don't understand what you mean. Can you expand?
Rationality prevents you from thinking a Soviet invasion of Poland followed by a break in US-Soviet relations is more likely than a break in US-Soviet relations. It doesn't help much in estimating either.
Noah Millman wrote:
Link (which includes additional good retrospectives) thanks to Ampersand.
This article may have more political content than is suitable for LW-- if you'd rather discuss it elsewhere, I've linked it at my blog. I've posted about it here because it's an excellent example of updating and of recognizing motivated cognition even if well after the fact.