Nightwatch, on the underwear bomber and "intelligence failure."
As in all past intelligence failures, the most critical failure is cognitive, meaning a person must recognize information is important before he or she recognizes the need to share that insight. There is no technology or technique in use that would ensure that perfect, unquestioning information sharing would have generated a warning to the airline industry, unless some recipient first discerned a credible threat in it. The probabilities of that occurring were zero because holders of similar information in different agencies all discounted or ignored it.
This problem is not about sharing. It is about the quality of the thinking. Those who had the information failed to recognize that it needed to be acted on. That is a cognitive failure of threat recognition and is the critical first step in any warning system. You have to see dots before you can begin to try to connect them.