What if the battle of Coral Sea never happened?

[Enterprise1934]

The battle of Coral Sea was a clear strategic victory to the Allies.
Not only that the Port Moresby invasion force was turned back; the battle also removed one third of the Japanese Navy's fleet carriers that would otherwise been available for the battle of Midway.

Had Adm Yamamoto never sent the Shokaku and Zuikaku to Coral Sea in support of Port Moresby invasion,
the first carrier battle in the pacific war would had been staged at Midway, instead of Coral sea.
That would had been quite a battle.

On the other side for the coming battle of Midway, instead of just the three Yorktowns,Adm Nimitz would had also been able to deploy the Lexington for the battle of Midway.

This changes the equation a little bit;
In the number of carriers, USN would have gone to battle at slightly worse odds (4:6) compared to historically (3:4).
To make things worse; Shokaku and Zuikaku were at the time the most modern of the Japanese carriers and they carry almost as many aircrafts as a Yorktown-class carriers - compared to Soryu and Hiryu which only carried 54-56 aircrafts each between them.

Nimitz would have known that this force is coming (from the code-breakers).
Given the knowledge that the stakes is now that much higher than historically;
Would the US Navy made available the Wasp or rushed the repair of Saratoga (she was only about 10 days late in joining the battle historically) to try even out the odds?
Or would any of the fast battleships been sent earlier to the pacific theater (as carrier escorts)?

For the battle of Midway itself;
Would both sides changed their deployment tactics (due to the greater number of carriers involved)?
Would the US still comes up as thriumphant as it had historically?
Would the Japanese able to prove otherwise?
What casualties that you would be expecting from both sides?

[lwd]

That's a tough one. For one thing the US has an extra day at least as far as the saiing time of the CVs. Do they have the planes to reinforce MIdway? If a day gives them the time to carry some as deck loads and send them to Midway before the Japanese get there. The Lexington and Yourktown will be not only there but in good shape with intact air crews. On the otherhand it was the fuel air explosion on Yourktown that initiated the USN practice of purgeing the gas lines with CO2 I beleive. Would this still be in place at Midway? If not the US CVs are more vulnerable. There's also likely to be a considerable difference in geometry and the Japanese search pattern was very important historically it may be more so in this what if as the CVs may be closer.

[alecsandros]

A tough one indeed.
Overall, the Japanese would have an extra 120-130 planes (for a total of 350-380), while the US would benefit from some 70 planes (for a total of 430 land and carrier based aircraft). From this, it would appear the IJN would have a slight advantage in the new scenario, but as LWD said, other changes could have had a much bigger impact on the battle.

Cheers

[RF]

It makes Japanese victory at Midway more likely, but overall wouldn't alter the course of the war - and certainly not the final result.

[Karl Heidenreich]

RF:

It makes Japanese victory at Midway more likely, but overall wouldn't alter the course of the war - and certainly not the final result.

The book "Shattered Sword" is enlightining in this regard.

Being a Yamamoto critic I think that he would have found the way to use the two new CVs in another "diversion" and that the main force at Midway could have been very similar to the historical one.

[tommy303]

Of course, one of the problems with Japanese strategy was it was too complex and all the diversions served mainly to weaken their own forces rather than that of the enemy. In the case of Midway, the diversion to the Aleutians did not get the reaction from the USN that the Japanese thought it would, and one can argue that a greater concentration of force might have been better for the IJN.

[lwd]

Shattered Sword If I remember correctly makes a pretty convincing argument that the Aleutions op was not a diversion but an entirely seperate op. Part of their condemnation of the plan was the Japanese trying to do too much. The Coral Sea op falls under this as well. While one may disagree with thier opinions in some cases that book should be read by anyone interested in this topic. The section on the Japanese comanders and the internal politics is worth it by itself.

[Karl Heidenreich]

In fact Shattered Sword is clear that the Aleutian operation was not a diversion but a mission by itself. Of course, diversion or not the Aleutian operation weakned the Japanese effort at Midway. My point is that Yamamoto thinking will go for another target instead of reinforcing their main force.

[RF]

I am not clear therefore as to the purpose then of the Aleutian operation, as the Japanese withdrew from the two islands occuppied after Midway.

[Bgile]

I am not clear therefore as to the purpose then of the Aleutian operation, as the Japanese withdrew from the two islands occuppied after Midway.

Kiska was evacuated over a year later, three months after the US invaded Attu and took it back after heavy fighting. The loss of Attu made the position at Kiska untenable. By that time it had become impossible to supply except by submarine.

So no, they didn't just decide to leave.

[neil hilton]

Wasn't the reason why the US got the drop on the IJN at Midway because one of the Japanese scout planes allocated to search the area where the US TF was was delayed? And thus Nagumo ordered another ground attack run.

If the Japanese scout planes had found the US TF 'on time' the battle would have been very different.

[Bgile]

Wasn't the reason why the US got the drop on the IJN at Midway because one of the Japanese scout planes allocated to search the area where the US TF was was delayed? And thus Nagumo ordered another ground attack run.

If the Japanese scout planes had found the US TF 'on time' the battle would have been very different.

That's true, and one of the US air groups was unable to find the target. There are decisions and errors and just luck that make a difference in many battles.

[neil hilton]

I think the real result for this scenario would be that Midway would have been even more decisive strategically than it was in reality. For whichever side won.

[lwd]

There is a real question of whether or not the US tries to intercept the Japanese CVs or not. I think it likey that they would 6:4 is not much worse than 4:3. If so they can get in position earlier as they won't be having to repair Yorktown. On the otherhand the US CVs may well be more vulnerable as it was the loss of the Lexingiton that instigated CO2 purgeing of the gas lines. If they leave earlier there is a good chance that they are closer to the Japanese fleet at dawn. This means a greater chance that they are discovered but also a greater chance that they find the Japanese CVs and fix them. The Japanese are still likely to have the problem of half their planes being on the Midway strike.

Even if the Japanese come out ahead in the carrier battle it isn't enough to turn the war around.
See:
http://www.combinedfleet.com/turningp.htm
and
http://www.combinedfleet.com/economic.htm