Operation Starvation was a WW2 American campaign to starve Japan into surrender by dropping 12,000 mines from B-29s into the narrow entrances to the Inland Sea and off Japanese ports. The idea was to deprive industry of coal, oil and raw materials and civilians of food. [see Lessons from an Ariel Mining Campaign. Project RAND. 1974. and
Operation Starvation. G A Mason. 2002.]
It is one of those historical events which I have never seen portrayed in a book, documentary or movie. Yet it was extremely effective. The mines sank or damaged 670 ships totalling more than 1,250,000 tons for the loss of only fifteen B-29s. Even more shipping capacity was lost because ships were held in port waiting for mines to be cleared.
Operation Starvation was part of one of three strategic options for ending the war against Japan.
The atomic bombing of Hiroshima and Nagasaki were justified by claiming that the alternative would have been a very costly invasion of the Japanese mainland. That was not true. There were three, not two, strategies by which Japan could have been induced to surrender.
Option 1 Invasion – Operation Downfall [the codename for the invasion of the home islands of the Japanese Empire] was scheduled for October 1945. The Japanese knew they could not win the war but hoped to avoid unconditional surrender by making invasion very costly. They had held 10,000 planes in reserve and had a good idea of the likely invasion sites. Downfall would have resulted in enormous casualties for both sides. There were various estimates of Allied casualties. One was five hundred thousand dead and over one million wounded. I suspect Downfall’s possible casualties were over estimated to justify the use of atomic weapons.
Option 2 Atomic bombardment
Option 3 Blockade and conventional bombardment by air and sea –
Blockade had proved very effective in cutting Japan off from its overseas possessions.
A glance at a map of the Japanese Empire in 1943 shows the reality of Japan’s strategic position and the actions necessary to ensure Japan’s defeat. The only way to connect the various parts of the Empire was by sea. Supplies had to go by merchant vessel. If an enemy could destroy its merchant fleet they could defeat Japan. Supplies would not be able to reach Japan and overseas garrisons would be cut off. The Japanese Navy was irrelevant except to protect the merchant fleet. Nazi Germany did not need to maintain control of the sea, Japan did.
Mining and submarine attacks had almost destroyed Japan’s shipping. Japan started the war with 6,500,000 tons of merchant shipping and 1,200,000 tons of smaller craft. By 1945 it had 1,466,900 tons left. Allied submarines proved to be very effective in destroying Japanese shipping. So much so that it was submarines, not battleships and aircraft carriers, that destroyed most of the Japanese merchant fleet.
Losses of merchant vessels combined with the capacity loss due to convoying significantly reduced Japanese economic strength. Imports of 16 key materials fell from 20 million tons in 1941 to 10 million tons in 1944 and 2.7 million tons in the first 6 months of 1945. The specifics were impressive: “Bauxite imports fell off 88% just between the summer and fall of 1944. In 1945, pig iron imports plunged 89%, pulp 90%, raw cotton and wool 91%, fats and oils 92%, iron ore 95%, soda and cement 96%, lumber 98%, fodder 99%, and not one ounce of sugar or raw rubber reached Japan.” Though the Japanese prioritised food shipments the average caloric intake fell 12% below the minimum daily requirement for the non-farming population in 1944.
Japanese oil imports fell from 1.75 million barrels per month in August 1943 to 360,000 barrels per month in July 1944. The Japanese Navy alone required 1.6 million barrels monthly to operate. After September 1943, only 28% of the petroleum shipped from the southern regions reached Japan. In the last 15 months of the war the figure was 9%.
After the firestorm raid on Tokyo that killed over 100,000 people B-29 raids had continued and had devastated large areas of many Japanese cities. Napalm proved very effective against Japanese buildings. Warships had bombarded industrial targets and carrier based aircraft carried out regular attacks on military targets and transport infrastructure.
The US Chiefs of Staff and the Army strongly favoured invasion. Certainly there would have been a bloodbath but what an opportunity for a general to show his mettle and earn a place in the history books.
The air force and the navy opposed invasion and favoured option 3. Both Nimitz and MacArthur, the commanders in the field, strongly favoured option 3. They considered that blockade and bombardment could make Operation Downfall pointless.
The wrong choice?
The US chose atomic bombardment to force Japan to surrender. Was that the right choice? Should they have chosen option 1 or option 3?
I doubt if US politicians would have chosen invasion in 1945 without giving option 3 at least another year. Invasion would have been very costly, in every sense. In contrast, blockade and bombardment was very cheap in men and material. The US only lost 614 aircraft during its raids on Japan out of a total of 9,949 bombers and 8,420 fighters and other aircraft lost in all theatres [the UK lost a total of 22,010 aircraft]. and would perhaps have not taken much longer to force surrender. There would, however, have been a lot of civilian casualties with both options..
Atomic bombardment was probably the cheapest and quickest option in the short term. It probably led to fewer casualties on both sides. In the long term it was a bad choice. The US demonstrated that it had and would use atomic bombs. That led to the Cold War which cost the US trillions of dollars and could have destroyed most life in the northern hemisphere.
How effective is blockading?
The WW2 German blockade of Britain [mainly by submarine] cost Britain 11,000,000 tons of shipping but did not produce mass starvation or drive it out of the war. In WW1 the British blockade of Germany is estimated to have killed over 460,000 German civilians through starvation and caused mass disaffection. Even the German Army was affected. When soldiers captured British trenches in the 1918 Spring Offensive they were astonished at the quality and quantity of the food available to the ‘Tommy’. [Ring of Steel: Germany and Austria-Hungary at War, 1914-1918. A Watson]
The little known British naval blockade of Spain [particularly of oil] deterred Franco from entering WW2 on Hitler’s side.
The US had to capture some of the Mariana Islands to bring its bombers within range of the Japanese mainland. Fighting anywhere else was pointless because if Japan could be forced to surrender its outposts would have to follow. It is hard to escape the conclusion that much of the land fighting in Japan’s outer empire was unnecessary, particularly the Philippines campaign. The map below shows the Japanese Empire on the day it surrendered. The areas in pink were still under Japanese control. It it is clear that many parts of the Empire were bypassed and their garrisons left to wither. Many were already in dire straits and there were many instances of cannibalism in the Outer Empire garrisons whose supplies had been cut off. The US drive was to capture islands to use as bases to bomb the Home Islands. The map also makes clear the irrelevance of the Philippines Campaign. That campaign seems to have owed more to MacArthur’s ego than strategic necessity.
In addition to the merchant ships U.S. submarines sank 700,000 tons of naval ships (about 30% of the total lost) including 8 aircraft carriers, 1 battleship and 11 cruisers. Of the total 288 U.S. submarines deployed throughout the war (including those stationed in the Atlantic), 52 submarines were lost with 48 lost in the Pacific. American submariners, who comprised only 1.6% of the Navy, suffered the highest loss rate in the U.S. Armed Forces, with 22% killed. The Germans lost 784 U-Boats and 28,000 men [a 68% loss rate]. The Royal Navy lost 79 submarines.