The Japanese hoped to lure the U.S. aircraft carriers into a trap, clearing the seas for Japanese attacks on Midway, Fiji, Samoa, and Hawaii itself. The plan was undermined by faulty Japanese anticipations of the U.S. reaction and poor initial dispositions. Crucially, U.S. cryptographers were able to determine the date and location of the planned attack, enabling the date and location of the planned attack, enabling the forewarned U.S. Navy to prepare its own ambush.