I'm reading A Patriot's History of the United States right now by Larry Schweikart and Michael Allen. They definitely have a conservative bent on the story, but are also willing to give credit where it's due. People love conspiracies these days, so they made an interesting comment on the idea that FDR knew that the Pearl Harbor attack was coming. One point they made was that people accuse FDR of looking for an excuse to get into the war--as if he didn't have plenty of them already! Nazi U-boats had been killing American sailors, sinking American ships, and generally being hostile for some time. They also pointed out how Roosevelt had received intercepted information. But intercepting is one thing. The code must be broken, then translated, then analyzed. We did intercept information. Some of it received in 1941 didn't make it through this process until 1945. We weren't in the computer age yet.
I think people often mistake conspiracies for trends and sympathies. That is not to say that there aren't powers out there that want to increase their influence. We need to look at their actions and strategies before crying foul, and when we do, the evidence must be concrete--not hysterical hype.