This quote is taken out of context. The people at that meeting were discussing what their standing orders to various commanders at American installations around the Pacific theater based on the intelligence that indicated that their was a very strong likelihood that the Japanese might stage an attack. They therefore instructed that the posts should be put on high alert (I’m not sure if that’s the technical term), but to avoid firing the first shot in the case of aggressive action by the Japs so that America could claim the moral high ground. Having a clear-cut case to take to the American people was very important in those days.