The planning on the attack took some time and some thought for the Japanese. They began planning the attack in early 1941. The Japanese Navy took several months to take the time to plan for this attack. It took a lot of their own time and their attention to get it all done. The intent of a defensive strike on Pearl Harbor was to neutralize American naval power in the Pacific, then removing it from influencing operations against American, British, and Dutch colonies to the south. Successful attacks on colonies were judged to depend on successfully dealing with the American Pacific Fleet. Planning had long anticipated that a battle between the two Fleets would happen in Japanese home waters after the US Fleet traveled across the Pacific, under attack by submarines and other forces all the way. The U.S. Fleet would be defeated in a climactic battle, just as had the Russian Fleet in 1905. A surprise attack posed a twofold difficulty compared to long standing expectations. First, the Pacific Fleet was a formidable force, and would not be easy to defeat or to surprise. Second, for aerial attack, Pearl Harbor's shallow waters made using conventional aerial torpedoes ineffective. On the other hand, Hawaii's isolation meant a successful surprise attack could not be blocked or quickly countered by forces from the continental U.S.…