Ok guys, I am almost afraid to post another thread here after the last one went 29 pages and 11400 views. LOL. But here goes.
Should the Japanese have made contingency plans for an amphibious assault on Oahu, immediately following the Pearl Harbor attack? The attack succeeded beyond what the Japanese had hope for (other then bagging the US carriers), as far as I can see, the way was open for a landing somewhere on Oahu island. The more I looked at it, the more feasible it seems. Some considerations.
- The Imperial navy was about 240 miles away when the planes were launched for the first wave. That is about 1 day's sailing to Oahu. If they had put up two more waves on Dec 7th to soften land targets preparatory to a landing the following day, they could in theory be off the coast of Oahu the next morning.
- They would have air superiority if they attempted a landing.
- They would have a choice of landing beaches throughout Oahu. I am not sure what the US Army strength on Oahu was during the Pearl Harbor attack, but they can't possibly defend all possible landing beaches, especially after the confusion, and casualties from the prior day's attack.
- The Japanese had conducted successful landings a few days later throughout SE Asia, so I am inclined to think they have some expertise in this. The level of opposition varied from their landings, but they were all successful in Malaya, Hong Kong, Dutch East Indies, Philippines, etc. There is a case to be made that they would have successfully landed on Oahu too. Especially with big gun support from their Battleships and cruisers, and air superiority. Naval gunfire as well as air superiority would have neutralized any counter attacks from US forces.
- They could have embarked a landing force of 15,000 troops, many would have been veterans of the China campaign. By comparison, they invaded Malaya at Kota Bahru with an initial force of about 8,000. They might have succeeded with this initial force. If the Dec 7th attack on Pearl Harbor had gone poorly, this landing force could have turned around and be dropped of at any of the other SE Asia invasion sites as reinforcements.
- They might have encountered a neutral or even friendly civilian population, with the largest ethnic group being Japanese of Nissei and Issei generations. Many of whom still speak japanese and have ties with their homeland.
- Strategically, this would have been a game changer. The US would have made the re-taking of Pearl Harbor the number one priority. But they would have been denied the use of Oahu as a staging base, and be denied all its ship repairing facilities, etc.
- The Japanese would also be in possession of of thousands of American POWs. Any american attempt to re-take Oahu has to account for this.
- I don't know how long the Japanese would be able to hold Oahu, given the logistics. But the island's sugar and pineapple plantations could be converted to growing food crops. Water would not be an issue either.
My thinking is they probably should have embarked an invasion force, and use it if the attack had gone according to plan on Dec 7th. Just my 2 cents.