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Pacific war: decisive battle doctrines

Posted: Fri Dec 21, 2018 2:51 pm
by Dave Saxton
Plan Orange:

The Color Plans were broad strategic plans developed by the US Military during the early 20th Century in case of war with various possible opponents. Plan Red was in case of war with Great Britain. Plan Black was in case of war with Germany. Plan Green was in case of war with Mexico and so forth. Plan Orange was in case of war with Japan.

Plan Orange always centered around the Philippines. It was accepted that in any war with Japan, that the Japanese would occupy the Philippines as one of their first moves. The US would then need to send a fleet to the Western Pacific to relieve or retake the Philippines.

This circumstance suited the USN, because they were imbued with the strategic doctrines of Admiral Mahan. Mahan preached that international power was established by completely defeating any opponent’s naval forces in decisive battle and establishing sea superiority throughout the strategic theater. A battle fleet sent to the Western Pacific would be challenged by the Japanese Navy for control of the sea there, setting the stage for decisive battle. It was expected that the decisive battle would be fought in the Philippine Sea between the Mariana Islands and the Philippines proper.

The First World War and its aftermath brought the need to amend Plan Orange with a revised plan accepted in 1924. This would actually be the first of more than 100 revisions during the next 12 years. From the navy’s point of view, the recent Battle of Jutland served as the basic model of the decisive battle they expected to transpire. However, technological developments such as the warplane and naval aviation, as well improvements in fire control, meant the Jutland type battle could be fought at longer ranges than the actual Battle of Jutland, using aircraft to scout and to observe and correct the fall of shot. Thus, the USN planned the design of its battle fleet to primarily fight a long-range gunnery engagement in relatively fair weather, and during day light, using aircraft spotting. This remained the primary prospectus of USN planners right through the 1930s.

In addition, the Japanese were mandated possession of many of the previously German held Pacific islands, as result of the Versailles Treaty. These islands became collectively known as the Mandates. These now Japanese held islands were in the way of USN advance across the Pacific and could be used as bases for land-based air forces. Provision for dealing with this situation would need to be provided.

Other developments also affected Plan Orange. One of the lesser known aspects of the Washington Treaty was that it prohibited the USN from developing advanced fleet bases in the Western Pacific. This meant bases in the Philippines and Guam could only be essentially refueling stops and not places to base a large battle fleet on a permanent basis. This meant that USN warship design would need to place an emphasis on long cruising range and/or reduced fuel consumption.

Re: Pacific war: decisive battle doctrines

Posted: Fri Dec 21, 2018 2:54 pm
by Dave Saxton
The US Army saw things very differently. For Army planners the main problem was that the Philippines were indefensible to invasion without a large battle fleet already in correct position to repel a Japanese invasion fleet. The largest practical army garrison that could be deployed to the Philippines during peacetime was only about 11,000 troops. The Japanese could easily land 30,000 troops within one week. Within one month they could realistically put 300,000 troops into the Philippines. The USN conceded this reality but it still fit into their Mahanian decisive battle doctrine, because defending or re-taking the Philippines provided the rationale to fight a decisive naval battle in the Western Pacific. To Army planners this was madness.

The US Army recommended just writing off the Philippines and taking on a defensive posture by establishing a line of demarcation from the Alaska though Hawaii and ending in Panama. This would be a strong defensive position that would accomplish what the Army considered the primary mission of defending North America, and would not be nearly as costly in terms of blood or treasure.

To the Navy, the Army’s point of view was anathema. This would essentially allow the Japanese to establish sea control throughout the Western Pacific on a permanent basis, and would inevitably lead to a negotiated peace allowing the Japanese to win out in a Mahanian sense, keeping their Western Pacific and Asian conquests. It would establish Japan as the world’s preeminent naval power.

War (board) games conducted at the USN War College indicated that the USN could defeat the Japanese Navy by fighting a series of battles as it advanced through the Central Pacific culminating in a Jutland like decisive battle in the Philippine Sea. Most of the 127 revisions to Plan Orange from 1924 resulted from these war games.

Nonetheless, the army remained intransigent. During 1936 the Joint Planning Board was tasked to hammer out some kind of a compromise. The compromise included the army’s idea of establishing a defensive posture, but only initially and then an advance through the Central Pacific. What to do about the Philippines was left open. This final revised Plan Orange went into effect by 1938. By 1939 it had been superseded.

Re: Pacific war: decisive battle doctrines

Posted: Fri Dec 21, 2018 3:01 pm
by Dave Saxton
Rainbow 5

Plan Orange was superseded, or a better term might be supplemented, by Rainbow 5. The Rainbow War Plans were drawn up to reflect the reality that no two nations were likely to fight wars exclusively between themselves. Rainbow 5 assumed war against Japan and Germany at the same time, and that the United States would be allied with Britain and France. Rainbow 5 considered that a war in Europe and the Pacific simultaneously would probably need to be prosecuted against either enemy in turn. If it was Germany first then the strategy in the Pacific theater would need to be defensive until Germany was neutralized. Then an advance through the Central Pacific could be undertaken culminating in a decisive naval battle. It is to be observed that Rainbow 5 is the general course the war in the Pacific took from September 1943.

The Dog Memo

Rainbow 5 became official strategy with the Dog Memo during 1940. The Dog Memo refers to paragraph D of a memo written to President Roosevelt by Admiral Stark. In paragraph D, Stark outlined Rainbow 5 and recommended the Germany First strategy. This was accepted by FDR and proposed to Churchill.

Re: Pacific war: decisive battle doctrines

Posted: Fri Dec 21, 2018 3:15 pm
by Dave Saxton
IJN decisive battle plans

The Japanese also were imbued with the doctrines of Mahan. Additionally, their own naval tradition included the Battle of Tsushima when a war was won by completely defeating the Russian fleet in a single decisive battle as recently as 1905.

The Japanese decisive battle doctrine also centered on the Philippines. In case of war with the United States, Japan planned on taking the Philippines as one of their first moves. Then they expected to defeat the USN in a decisive battle to be fought east of the Philippines proper as the USN advanced across the Pacific to relieve the Philippines.

The Japanese decisive battle plan was divided in to two phases and each phase consisted of two parts. The first phase was the Attrition Phase. The first part of the attrition phase was to be the job of Japanese submarines. Submarines were to whittle down the American battle fleet using a new super torpedo. Japanese submarines were intended mainly to be used against enemy warships and not to fight a war against commerce such as was fought by German U-boats and American submarines. (it should be noted that the IJN gave little thought to protecting their own shipping lanes from commerce warfare during a protracted war)

Then as the American battle fleet neared the Mandates, the war of attrition was to be taken up by torpedo bombers. These torpedo bombers were to be both from carriers and from island outposts. Thus, such torpedo bomber designs as the Betty began development. This was the second part of the attrition phase.

Decisive Battle Phase

After the USN battle fleet had been worn down by attrition it was to be destroyed in night battle by torpedoes. The destruction of the enemy battle fleet in night battle was the primary part of the decisive battle phase. The weapon delivery platforms to delivery the agents of destruction (Long Lance torpedoes) during this night battle were to be cruisers and destroyers supported by fast battleships (the Kongos). The Japanese invested heavily in training for night battle using the torpedo as their main weapon.

Come day light, should it still be required, the job of finishing the complete destruction of the enemy’s battle fleet would be completed by the Japanese battle fleet. This was part two of the decisive battle phase.

Re: Pacific war: decisive battle doctrines

Posted: Fri Dec 21, 2018 4:19 pm
by OpanaPointer
It's rather pointless to talk about plans there were never used. WPL-46 was the plan we went to war with.

Re: Pacific war: decisive battle doctrines

Posted: Fri Dec 21, 2018 8:25 pm
by Dave Saxton
WPL-46 is Rainbow 5

Re: Pacific war: decisive battle doctrines

Posted: Fri Dec 21, 2018 10:37 pm
by OpanaPointer
Dave Saxton wrote:
Fri Dec 21, 2018 8:25 pm
WPL-46 is Rainbow 5
Yep. But Orange was superseded by Rainbow-5. I have the other Rainbow plans online somewhere.