The article http://www.straightdope.com/mailbag/mpearlharbor.html summarises the general facts but glosses over the more compelling reasons why the belief of prior knowledge exists.
In the first instance, the article doesn’t discusss why the US was in negotiations with Japan, nor why the Japanese diplomatic ciphers (purple etc) were broken.
A quite reasonable explanation for the war between the USA and Japan is that the USA forced Japan into it. The US used coercive negotiations calculated to create an impossible situation for Japan in order to gain economic and political advantage. They did this using all diplomatic and spying resources available. Routine reading of all top level Japanese diplomatic cables was part of this process. The US knew exactly how far Japan would go, and then pushed just that much harder.
Given the ability to predict and partially direct the Japanese response, the US was clearly in no doubt about the eventual outcome, a state of war between the US and Japan.
Why the US did this is better left to students of mid-century geopolitics. That they did do this is in no doubt.
Regarding prior knowledge of the Pearl Harbour attack, there is less evidence. But at the very least the US was expecting some attack on itself. It was in fact quite reasonable for them to expect this, as it created an impression of the US being a victim rather that an agressor.
There also is the possibility that the US did in fact know precisely what was going to happen, but did nothing for fear of compromising their intelligence sources.
Perhaps the US did not expect such a dramatic reaction, but they did expect some reaction. They also expected that reaction to create a massive wave of support for the Goverment in prosecuting war against Japan, and also Germany. They got what they wanted.
Pearl Harbour can only be listed as an event deliberately created by the US, but not necessarily one they expected.