So the Third question is then, the big what - if.
I know this gets us in trouble sometimes because some folks get too literal minded about it. We know the Japanese lost Midway and lost the war in 1945 etc. But this is just some speculation. What is the Japanese had won Midway and maybe one or two other battles after that, and the Americans had been forced to recoil into a defensive posture.
Well that means the Japanese would have been able to consolidate some of their gains closer to home, places with some Strategic resources and geographical value like Formosa, Indochina, Indonesia, Malaysia and the Philippines. It would have given them some time to build up their forces, maybe even improve training (the feasibility of this is an open question for me maybe someone else knows in detail) But what else could they have done?
One thing that seems likely to me is that they could have gone back into the Indian Ocean and done some real damage.
Reading about their
short spring 1942 Indian Ocean / Ceylon raid, it looks like in a very short time they did some very serious 'Blitzkrieg' damage to the (mostly) British forces there, and if they hadn't had their hands so full dealing with the Yanks in the Pacific, I wonder how much Strategic damage they could have done in the Indian Ocean to British supply lines ?
From the way that raid went down, it looks like at that time in 1942 the Royal Navy was not ready to handle the IJN. The surface fleets were about equal, with a slight advantage for the British (5 battleships, 7 cruisers and 15 destroyers for the Royal Navy, plus about 30 frigates, armed merchantmen etc., with 4 battleships, 7 cruisers, and 19 destroyers for the IJN). But the Japanese had enough of an advantage in aircraft (both qualitatively and numerically at about 3-1 in planes) with 5 aircraft carriers vs. 3 for the British.
The results were very lopsided, and reminiscent of the opening Blitzkrieg assault of the IJN - the Royal Navy lost 1 carrier sunk, 2 heavy cruisers, 1 'armed merchant cruiser', 1 corvette, 1 sloop, 23 merchant ships and 40 aircraft. The Japanese lost ~20 aircraft. Certainly no devastating attrition of aircrew.
In the air, the Royal Navy's compliment of Fairey Fulmars, Swordfish, and Albacores, supported by land based Blenheim's and Hurricanes, proved incapable of withstanding the onslaught of Japanese air raids and unable to sink Japanese ships. Some examples -
A flight of Blenheim's makes a strike on the IJN fleet, they lose 5 planes and score zero hits. Would SBD's have been more useful there? I think so. For that matter A-20's might have gotten a couple of hits.
During the infamous
Easter Sunday raid, according to the Wiki the RAF and FAA lost 27 aircraft, mostly Hurricanes, while the Japanese lost five. The wiki claims that 90% of the Japanese dive bombers hit their targets. That means they were relatively free of danger because they did not by comparison do quite that well at Midway or in the Solomons.
If the Japanese had been able to continue this kind of action a bit more, and if the Germans had won El Alamein which he have also been discussing, it might have gotten ... dicey for the Allies. Certainly Winston Churchill thought so:
"
The most dangerous moment of the War, and the one which caused me the greatest alarm, was when the Japanese Fleet was heading for Ceylon and the naval base there. The capture of Ceylon, the consequent control of the Indian Ocean, and the possibility at the same time of a German conquest of Egypt would have closed the ring and the future would have been black. "
So IMO, the
TL : DR is - if the Japanese had decisively won at Midway, they may very well have won in the Solomons, and bought themselves some time to do real damage to British forces in the Indian Ocean, perhaps capturing Ceylon, thereby causing serious Strategic Injury to the British War Effort. And perhaps affecting the outcome of the War.
A lot of big ifs there of course, and we know this did not actually happen. Just some food for thought.