I feel like Japan could have actually invaded and captured hawaii and that would have been big. They thought big but not big enough
Without the base at Pearl it would have been far harder for us to persecute the war. However, given that our strategic plan was to end the war in Europe and then turn to the Pacific the end result would have been the same although it would have taken longer. Hawaii gave Japan nothing strategically other than it deprived us of our most important base in the Pacific. It was beyond most of the Japanese conquests.
By the end of the war we were producing a dozen or more carriers for every one that Japan could make and they were equipped with better planes and pilots than the Japanese. Japan simply did not have the resources to defeat us and given the juggernaut of the Red Army they would have certainly lost all of China and beyond.
The Japanese didn't have the heavy lift to move the required number of troops needed to take Oahu, the amphibious know-how needed to attack a defended beach, or the cargo capacity necessary to supply their invasion force plus the civilian population they took. And the Japanese knew that. They never seriously considered invading Hawaii.
They could have conquered the islands if they had more nasty fossil fuels. In fact, Japan struck Pearl Harbor so that they could strike the Dutch East Indies with impunity in order to obtain those precious fossil fuels without which they could not have waged war in the first place.
The US Army establishment on Oahu would have been a tough nut for the Japanese. It would have required moving an entire Japanese Field Army (about a corps-size unit in US terms) and keeping it supplied for weeks of heavy fighting. The fighting on Oahu probably would have rivaled that on Bataan-Corregidor and being as it was much more distant the outcome would likely have been different from that battle.
“I feel like Japan could have actually invaded and captured hawaii and that would have been big”
They never had the ability to pull that off. Their supply lines would have been insane and enormous. And they had some brutal strengths, but forcible entry beyond friendly aircover was not one.
And don’t kid yourself, Hawaii was very strong. In October 1941, the US Army reorganized the Hawaiian Division, considered a square division with its four infantry regiments, into two new smaller divisional units, the 24th and 25th Infantry Divisions. The new triangular divisions were each augmented with regiments from the Hawaiian National Guard, bringing the divisions up to the three infantry regiments allotted in the Army’s new Table of Organization. In addition, four anti-aircraft artillery regiments, nearly four full coast artillery regiments, and a company of light tanks with supporting troops made up the Army garrison as of December 1941.
The coast artillery was 8 inch and 14 inch.
The Japanese struggled for 16 days to take Wake Island from 500 Marines armed with 6 five inch 51 caliber guns and one squadron of 12 planes.
Hawaii was simply not possible for them to do anything but a a sneak “hit and run” attack.
For perspective, Imagine if the Japanese held Hawaii, think of the size of the force WE would have needed to take it on late in the war. The Japanese were just not capable of forced entry and it’s logistics that we were. They never even built a decent landing barge.