 Yamamoto is grimly pleased with the results thus far but he is troubled by reports that the Japanese Foreign Ministry failed in their mission to deliver a formal declaration of war to the US prior to the air attacks, thus allowing the Americans to brand them as ‘sneak attacks’, igniting their anger and righteous indignation.Yamamoto knows that the US Navy possesses at least three aircraft-carriers in the Pacific theatre.He despatches two of his battleships, the "Hiei" and the "Kirishima", to mount a nocturnal bombardment of Pearl Harbor, hoping to provoke a counter-strike by the US carriers, thus exposing the location of the latter.