What was the U.S.'s strategic plan in the Pacific War?

by to_change

I am currently reading Parshall and Tully's "Shattered Sword: The Untold Story of the Battle of Midway" and it goes into great detail into the strategic planing process that occurred between Yamamoto's Combined Fleet Staff and the Japanese Naval General Staff as they were deciding what the military's next steps should be after a staggeringly successful first phase of operations. Parshall and Tully go into this detail because they make a key claim in their book that this planning process was dysfunctional and played a role in the poor operational decisions made for Midway. However, I have never seen a similar analysis done for the U.S. side of the war. Even the books about battles like Coral Sea and Midway, generally have the U.S. in a reactive position, intercepting communications and figuring out Japanese intentions followed by successful reactions. Even one we get to Guadalcanal, the operation is framed as a unilateral concoction of Ernst King which was forced upon Nimitz, Ghormley and subordinate commanders.

With that in mind, I had a set of questions:

  1. What was the post-Pearl Harbor U.S. strategic plan for the prosecution of the Pacific War? Of particular interest is the post-Midway U.S. assessment and plan, given that this battle allowed the U.S. to begin mounting offensives in a way that was not possible before.
  2. How did the U.S. strategy change given the shift from reliance on Battleships => Carriers? Prior to the war, the U.S. strategic plan was "Plan Orange", which called for a decisive battle to be fought in the pacific using battleships. How did that plan change as a result of the battleships being at the bottom of Pearl Harbor?
  3. By what process did U.S. planners arrive at their chosen conclusion? What were the alternatives proposed by different factions? Why did the ultimately successful faction prevail?
  4. Are there any good resources on this topic?

Thanks in advance!

DBHT14

What was the post-Pearl Harbor U.S. strategic plan for the prosecution of the Pacific War? Of particular interest is the post-Midway U.S. assessment and plan, given that this battle allowed the U.S. to begin mounting offensives in a way that was not possible before.

How did the U.S. strategy change given the shift from reliance on Battleships => Carriers? Prior to the war, the U.S. strategic plan was "Plan Orange", which called for a decisive battle to be fought in the pacific using battleships. How did that plan change as a result of the battleships being at the bottom of Pearl Harbor?

I would say this is a fundamental misunderstanding of what exactly WPO and in general US thinking about a Pacific war involved.

At its core, WPO and its successor the Rainbow Plans, were far more than just the USN seeking called for a decisive sea battle between fleets with their gunlines in range of each other. The Rainbow Plans incorporated a strategic reality where the Pacific would not be the only or even the primary theater where the US was making war. This thought process is best distilled into the Plan DOG Memo by CNO Stark, which contemplated the US entering the war in Europe to keep the Allies in the fight and that the European Axis were the more important threat to counter first.

This of course meant a de-prioritzation of the Pacific, but even this was not totally unsupported in the old ORANGE plans. While it went through several iteration, by the late 30's it was a cautious and measured strategy. The fleet would no longer be rushed to the Philippines to seek an early confrontation with the IJN. It called for upwards of 6 months of the main body of the Pacific Fleet being restricted to Hawaiian waters, or no more West than Midway. This time would be used to complete mobilization of reservists, ships from other postings arrive, and the force made ready to start the offensive.

Which it shouldnt be surprising was planned to be a cartwheeling amphibious offensive, seizing island bases, and allowing the fleet to establish forward bases until either the IJN was defeated or the Japanese Home Islands could be brought under blockade. This was supported by a USMC that had spent the previous +20 years thinking about how to conduct amphibious landings, and developing a remarkably robust doctrine and understanding of the litany of specialized equipment they would need.

While the SLOC to Australia were not initially a critical consideration, so the Solomons were not thought of as the first target, the great Central Pacific Offensive of 1943-44 traveled well known paths. The Japanese Mandate Island chains of the Marshall, Caroline, and Mariana chains were studied by naval planners for ideal landing spots for forward bases. Add to this the Gilbert islands seized by Japan early in the war and the USN had no shortage of options to consider. So in essence we see the concept laid down in ORANGE just tweaked to support the increased importance of the South Pacific and Australia as a priority. But even then we can see the long term planning to stick to what the USN wanted to do. There is a reason that the USN sent their brand new Essex class hulls to Pearl to build up a coherent force vs feeding them in a trickle into the Solomons in 1943. The front was stabilized enough, time to get back to the larger plan, and of course shore based air was much more robust in the South Pacific!

As to the role of carriers and naval aviation in general it should be noted that the USN was certainly not blind to their usefulness before the war. The Fleet Problems every other summer had proven the effectiveness of scouting formations, and the increasing maturity of the community meaning new generations of aircraft could more effectively attack ships. While the seized island bases were initially meant to be friendly anchorages, their ability to serve as forward airbases was a factor as the 1930's went on. While at sea the need for carriers to be an integrated part of the fleet was not ignored. Different options were considered, from pairing 3 battleships and 1 carrier and escorts as a tactical group, to splitting off the carriers and heavy cruises. All part of the frankly dizzying complexities of the dual Administrative and Tactical organization and command splits of the Pacific Fleet by the late 30's. But that they had a role to play was clear, along with the need for more, remember the USN put in orders for the first Essex hulls before the war!

So you have the USN with a mature vision of how they wanted to fight against Japan.

  1. Build-up strength by restricting the fleet to Hawaii/be defensive for 6 or so months
  2. Cartwheel through the Japanese possessions in the Central Pacific
  3. Either defeat the IJN in open battle or otherwise attrition them down to allow the Home Islands to be blockaded

And yep that looks pretty familiar, and is mostly agnostic as to the actual composition of the fleet doing the work.

How did that plan change as a result of the battleships being at the bottom of Pearl Harbor?

While on a minor point here, remember most the pre war battleship force was back in service within a few months! The USN just was not interested in risking them. so Task Force 1 as they were called was kept in California for most of 1942-43. Even before the war the USN was concerned about the age of the battle line and the IJN's relative speed advantage Kongo and Nagato classes, hence part of the motivation in emphasizing speed to keep up with lighter forces in the new generation of American designs.

War Plan Orange

If you want to learn more about how WPO developed and how it was applied in wartime there is no better work than:

War Plan Orange by Edward Miller

It especially traces the back and forth between groups advocating a quick rush across the Pacific and a slow build-up that you may find illuminating.

Black Shoe Carrier Admiral by John Lundstrom is also a worthwhile read, it is an operational biography of Fletcher, who of course was deeply involved in prewar and early war operations.