[mookiemookie]

I think someone hit it on the head earlier...U.S. and Japanese naval doctrine in those days centered around a "winner take all" naval battle between capital ships, and thus they were the first target. I doubt Japan had the foresight to understand what unrestricted submarine warfare would do to their plans in the Pacific. Funny, as the Battle of the Atlantic was in full swing at this point and the effect U-boats were having was readily apparent.