War Plan Orange

War Plan Orange (commonly known as Plan Orange or just Orange) refers to a series of United States Joint Army and Navy Board war plans for dealing with a possible war with Japan during the years between the First and Second World Wars.

Informal studies as early as 1906 covered a number of possibilities, from basing at Gibraltar or Singapore^[1] (an idea revived by the British before World War II)^[2] to "a quick trans-Atlantic dash" to the Pacific.^[3] The plan eventually adopted was conceived by Rear Admiral Raymond P. Rodgers in 1911.^[4]

The plan was formally adopted by the Joint Army and Navy Board beginning in 1924.^[5] Predating the Rainbow plans, which presumed the assistance of allies, Orange was predicated on the U.S. fighting Japan alone.

As originally conceived, it anticipated a withholding of supplies from the Philippines and other U.S. outposts in the Western Pacific (they were expected to hold out on their own), while the Pacific Fleet marshaled its strength at bases in California, and guarded against attacks on the Panama Canal. After mobilization (the ships maintained only half of their crews in peacetime), the Fleet would sail to the Western Pacific to relieve American forces in Guam and the Philippines. Afterwards, the fleet would sail due north for a decisive battle against the Imperial Japanese Navy's Combined Fleet, and then blockade the Japanese home islands. This was in keeping with the theory of Alfred Thayer Mahan, a doctrine to which every major navy subscribed before World War II, in which wars would be decided by engagements between opposing surface fleets^[6] (as they had been for over 300 years).

Rodgers' concept was closer to the one ultimately used in the Pacific War: a "leapfrog" campaign to conquer the Marshalls and Carolines (held by Japan before the war); liberation of the Philippines; and blockade.^[7] Absent was the "decisive battle" of Mahan, and of Japanese planning.

American war planners failed to appreciate that technological advances in submarines and naval aviation had made Mahan's doctrine obsolete. In particular, they did not understand aircraft could sink battleships, nor that Japan might put the U.S. battleship force (the Battle Line) out of action at a stroke—as in fact happened at Pearl Harbor.

American plans changed after this attack. Even after major Japanese defeats like Midway, the U.S. favored a methodical "island-hopping" advance, never going far beyond land-based air cover.^[8] Meanwhile, blockade was imposed from the very beginning of the war, with the first American submarine, Joe Grenfell's Gudgeon, arriving off Japan on about 31 December.^[9]

A number of requirements grew out of Orange, including the specification for a fleet submarine with high speed, long range, and heavy torpedo armament.^[10] These coalesced in the submarine Dolphin^[11] in 1932 (only to be rejected and returned to with the Gato class in around August 1941).^[12] The demand for submarines of this size also drove the development of the notorious Mark XIV torpedo (and its equally notorious Mark VI exploder), under the guidance of Commander^[13] Ralph W. Christie.^[14] The Navy also spent "several hundred thousand dollars" to develop powerful, compact diesel engines, among them the troublesome Hooven-Owens-Rentschler (HOR), which proved useful for railroads.^[15]

Japanese plans

The Imperial Japanese Navy developed a counter-plan to allow the US Pacific Fleet to sail across the Pacific while using submarines and carrier attacks to weaken it. The Japanese fleet would then attempt to force a battle against the weakened U.S. fleet in a "decisive battle area", near Japan (see Kantai Kessen), also in line with Mahanian doctrine, which Japan had enthusiastically embraced. It was the basis for Japan's demand for a 70% ratio (10:10:7) at the Washington Naval Conference, which was considered necessary to provide Japan superiority in the "decisive battle area", (taking into account that the United States had naval commitments in other theaters, while Japan did not), as well the U.S.'s insistence on 60%, which amounted to parity.^[5]

Outcome

Actual events were very close to the final plan. Carrier battles overshadowed surface action, but the "leapfrog" campaign was very much as anticipated.^[16]

The Imperial Japanese Navy, obsessed with the "decisive battle", ignored the vital need for defence against submarines.^[17] Germany and the U.S. demonstrated the need for this with their submarine campaigns against Allied and Japanese merchant shipping respectively. The American campaign ultimately choked Japan's industrial production and paralyzed her navy. Japan also notably failed to institute an anti-commerce campaign herself; systematic use of commerce raiders could have made Allied operations much more complex and conquering and holding Japanese-held islands more difficult.^[18]

See also

• Pacific War
• Rainbow War Plans

References

1. ^ Holwitt, Joel I. "Execute Against Japan", Ph.D. dissertation, Ohio State University, 2005, p.131.
2. ^ Miller, War Plan Orange.
3. ^ Holwitt, p.131.
4. ^ Holwitt, p.131; Vlahos, Michael. The Blue Sword (Newport, RI: Naval War College Press, 1980), p.163.
5. ^ ^{a b} Miller, Edward S. (1991). War Plan Orange: The U.S. Strategy to Defeat Japan, 1897–1945. Annapolis, MD: United States Naval Institute Press. ISBN 0870217593. 
6. ^ Mahan, Alfred Thayer. The Influence of Seapower on History, 1660–1783. Boston: Little, Brown, copyright 1918, reprinted 1949.
7. ^ Holwitt, p.131.
8. ^ Willmott, H.P. (1983). The Barrier and the Javelin: Japanese and Allied Pacific Strategies, February to June 1942. Annapolis, MD: United States Naval Institute Press. ISBN 0870210920. 
9. ^ Blair, Clay, Jr. Silent Victory (New York: Bantam, 1976), pp.107 & 110.
10. ^ Holwitt, pp.130 & 132-3.
11. ^ Lenton, H. T. American Submarines (New York: Doubleday, 1973), p.35.
12. ^ Lenton, pp.61-63. The Salmons and Tambors were a trifle smaller, while the Cachalots and Porpoises were really too small for the Pacific, and too slow for fleet operatons. Lenton, pp.37-39, 45-47, 55, & 58; Blair, p.60.
13. ^ Holwitt, p.147fn52.
14. ^ Blair, p.61.
15. ^ Blair, p.61.
16. ^ Miller, pp.323-346; Vlahos, Michael. The Blue Sword (Naval War College monograph series, Newport, RI: Naval War College Press, 1980), pp.113-121.
17. ^ Parillo, Mark (1993). The Japanese Merchant Marine in World War 2. Annapolis, MD: United States Naval Institute Press. ISBN 1557506779. 
18. ^ Miller?

Further reading

• Miller, Edward S. (2007). War Plan Orange: The U.S. Strategy to Defeat Japan, 1897–1945. Annapolis, MD: United States Naval Institute Press. ISBN 1591145007.